What is the most useless thing you still have memorized?

The phone number at my home growing up as a child. The building is gone, the phone is gone. The number remains.
- I was talking with my wife about that a couple weeks ago, how I can remember my childhood home phone number, but don't even know my own actual phone number.
- Me too. Back then you had to know your numbers by heart and thats the only one I still know.
  It did help that it was only 4 digits after the area code
  
  Your city only has 4 digit phone numbers??? Where do live??? The place phones were invented???
  (That joke would play better if everyone knew where phone numbers were first installed, and I could just say the city name....ok, let me try something else)
  Where do you live??? In Alexander Gram Bell's living room???
  Meh.
- This is useful for passwords though a 11 pretty random string of numbers to add to the end of a passphrase
  
  a.k.a. salting
- Same here. Also my grandparents and a few others. Ironically I can't recall any numbers besides my own these days

0118 999 881 999 119 725 ... 3
- Well that’s easy to remember !
  
  What's so difficult about remembering 911?

The mitochondria is the powerhouse of the cell.
- Yesss

My ICQ number
- Uh-oh
- Your what?
  
  ICQ, one of the first messengers. Every user had a unique number, like phone numbers today.
  https://en.wikipedia.org/wiki/ICQ

The produce codes for bananas, green grapes, red grapes, and cucumbers, from my first job 28 years ago.
- I still remember the codes for the two different chicken patties McDonald’s had while transitioning from one to the other. We were desperate to get the old one out of the system but you could only do so after it was unused for 90 days. I went as far as renaming it so that it would be obvious for order takers not to use it.

X equals negative B
Plus or minus the square root
Of B squared minus 4AC
All over 2A
Sang to the tune of pop goes the weasel.
I haven’t done pre-calc in like 10 years, but this song still lives rent free in my head.
- I learned similarly but to the tune of the Flintstones theme.
  "Neg B / Plus or minus / Square root of b squared minus 4AC / It's all / Over 2A / That's the quadratic formul-ee" (to rhyme with 4AC).
- You can also do it to the chorus of Rollin' in the Deep. I teach both to my Algebra students.

"Why, Mr. Anderson, why?
Why do you do it? Why get up? Why keep fighting?
Do you believe you're fighting for something, for more than your survival? Could you tell me what it is, do you even know? Is it freedom or truth? Perhaps peace. Could it be for love?
Illusions Mr. Anderson, vagueries of perception. Temporary constructs of a feeble human intellect trying desperately to justify an existence that is without meaning or purpose.
And all of them as artificial as the Matrix itself, although only a human mind could invent something as insipid as love...
You must be able to see it Mr. Anderson, you must know it by now. You can't win, it's pointless to keep fighting!
Why Mr. Anderson, why?! Why do you persist?!"
Typed from memory.
- That was a fun read
- c/CommentsYouCanHear

8-6-7-5-3-0-9
- Jenny, I've got your number.

0118999881999119725…3

I before E, except after C, and when rhyming with "a," as in "neighbor" and "weigh."
Useless because it's wrong.
- It works for most words that aren't weird
  
  I see what you did there.
- What difference does that make?

I pledge allegiance, to the flag...
- Of the United States of America…
  
  And to the Republic, for which it stands...

Genesis Exodus Leviticus Numbers Deuteronomy Joshua Judges Ruth 1st Samuel 2nd Samuel 1st King 2nd Kings 1st Chronicles 2nd Chronicles Ezra Nehemiah Esther job psalms proverbs Ecclesiastes song of songs Isaiah Jeremiah Lamentations Ezekiel Daniel Hosea Joel Amos Obadiah Jonah Micah Nahum Habbakuk Zephaniah Haggai Zachariah Malachi
I'm pretty sure I can do the New testament also but I think you get the point.
- Something something Bible. I have no idea what any of this means.
  
  It's just the list of the books of the old testament.
  I went to a Christian School and one of the tasks one quarter was to memorize them and recite them.
  After you've done it a handful of times you realize that there is a rhythm or a cadence to the words and it's easier to memorize them by memorizing the cadence then it is by memorizing the words themselves.
- Aaargh, me too. I can still hear Sister Bernadette singing and see her little spectacled face bobbing from side to side as she taught us the songs.

Johann Gambolputty's full name.
Konami Code.
How to read UPC, EAN, and ISBN bar codes.
Why Will Hunting shouldn't join the NSA.
The Doomsday Method for determining the day of the week given any date after the Gregorian Calendar went into effect.
Pi to 260 decimal places
Everything you ever wanted to know about the Retro-Encabulator.
- I was going to say Pi to 124 decimal places from Pi day at school.
  I also have "Ickle me, Pickle me, Tickle me too" by shel Silverstein memorized. Same with "These woods" by Robert Frost.
  I have lots of random facts that I usually only remember when the topic comes up, but all are equally useless
- I need a new prefamulated amulite baseplate. Do you know where I could find one?
  
  One surmounted by a malleable logarithmic casing? I hear Rockwell sells them.

Two all beef patties special sauce lettuce cheese pickles onions on a sesame seed bun
- 30 years from now, when McDonald's brings that back, you'll be a trendsetter.

Proverbs 27:14
"He who blesses his neighbor with a loud voice early in the morning, it will be counted as a curse to him."
- Or the updated version:
  Mornings are for coffee and contemplation.
  
  Someone tell my fucking kids.
  5:30 am comes early.
  
  Coffee. And. Contemplation.

icq number

My wife gets an honorable mention for being able to recite the "what did you say to me you little bitch" copypasta in its entirety on a dime and as fast as she can say it

Pneumonoultramicroscopicsilicovolcanoconiosis

I had a lab TA in college who made it a point to teach everyone how to pronounce his name. But that's about it. He wouldn't help you unless you an attractive blonde woman.
So fuck you, Ashitosh.

The missile knows where it is because it knows where it isn't...

A static shock is 4116° for such a short fraction of time that it doesn't burn you

Where every single key item is located in the original Resident Evil 3 as well as how to solve all puzzles in the fastest way possible. Even tho I didn’t play it in 20 years.
The phone number in the house I grew up in. Seems to be a trend with the users here.
That Viggo Mortensen broke his toe in that one scene in The Two Towers where he kicks the helmet.

4 8 15 16 23 42
- what do they mean?!

Some old phone numbers that no longer work.
- As long as you don't use your old home phone number, the old phone numbers permanently lodged in your brain make good pin codes for stuff

I bomb atomically Socrates' philosophies and hypotheses Can't define how I be dropping these mockeries Lyrically perform armed robbery Flee with the lottery, possibly they spotted me Battle-scarred Shogun, explosion when my pen hits
Tremendous, ultraviolet shine blind forensics I inspect you, through the future see millennium Killer Bees sold fifty gold, sixty platinum Shackling the masses with drastic rap tactics Graphic displays melt the steel like blacksmiths Black Wu jackets Queen B's ease the guns in Rumble with patrolmen, tear gas laced the function Heads by the score take flight incite a war Chicks hit the floor, die hard fans demand more Behold the bold soldier, control the globe slowly Proceeds to blow, swinging swords like Shinobi Stomp grounds and pound footprints in solid rock Wu got it locked, performing live on your hottest block
- I am the hip-hop-potimus, my rhymes are bottomless...

Deoxyribonucleic acid.
My brain made it into a jingle and now I can't ever forget it.
- Welcome to gene engineering company, you're hired!

Have you heard of Swiss cheese? Here's a song that tells you all about it. (This was my only line from a play in the 1st grade. I'm 50 now.)
You can't handle the truth! (I know that whole monologue by Colonel Jessep.)
my old Wells Fargo checking account number from 20+ years ago
my student ID number from my first university 20+ years ago

Yo tengo un pollo en mi cabeza.
J'ai un poulet sur mon tête.
- Pardon je ne comprends pas.
  Only thing I remember from French class. But quite useful, when you are in France and don't speak French.

The Weird Al Show theme song
- OP asked for useless information

Pi to 30 digits.
- Pi to about 150 digits. Fun fact, if you knew the exact diameter of a circle the size of the known universe, and wanted to calculate the circumference to within the width of an atom, you'd only need about 40 digits. More than that is pure overkill for any practical application.
  
  I memorized up to the first zero and figured that would be fine for any interstellar cartography that I might get up to.
- Not so useless considering digits of pi make for the best passwords.

1€ is 6,55957 french francs
It was not even useful in 2000 to 2005 when people needed to calculate the conversion, because I was just a kid, but my mom made me remember this for some reason
- Same, but 5,94573 Finnish marks!
  
  40,3399 Belgian francs!

All the lyrics to Weird Al's "Hardware Store"
- Oh dang I wasn't going to contribute to this thread, but you reminded me that I know all the lyrics to the Weird Al Show theme song.

My previous credit card number.

macbeth soliloquy and a poem I was required to memorize in high school which I managed to do even though it took extreme effort because of the way my memory works. similarly because of the strange way my memory works I basically know them 30 or 40 years later now but it can take a little time for me to get them going. I actually have pulled out the soliloquy a few times in internet comments so not totally useless.
- Ah see I have the opposite problem. I memorized the whole thing in 30 minutes but I didn't know it the next day.
  
  I think thats the normal thing. sucks because I could never effectively cram but on the other hand what I learn tends to have longer term value.

I vibe most with wavelengths of 490 to 500 nanometers, but right now I'm feeling a little magenta.

In Australia there is a reading and writing hotline to help you lean English.
I don't live there but I still remember the number. 1300 655 506
- Wow, that's a cool initiative

My dads phone number. My childhood friends phone number. Both are useless because they haven't been in service in 20 years.

In old versions of minecraft java edition, if you punch something while running, you wont lose hunger from it

After learning the phonetic alphabet I thought it would help when I'm spelling out my last name to people to say 'let me spell it out phonetically'. Most of the time I get a blank stare and then they have me repeat each letter, many of which sound similar.

Chemical elements put to a possibly recognizable tune.

Some animal facts, useless stuff.
- Don't keep us in suspense ~ what animal facts?

My student number from many years ago. My last 2 credit card numbers. Have some digits of pi memorized, useless to daily life.

The first ten digits of pi rounded up 3.141592654 seemed a lot more useful during undergrad.
- According to some, 37/38 decimal places is where additional information, even at cosmic scale, becomes fairly useless.
  At 15 decimal places, you can calculate a circle from Earth around the Voyager 1 probe, and find the circumference with an error of about half an inch. (About 15 billion miles/24 billion km in radius)
  So to say you need even 9 decimal places of precision while using pi for anything on earth, would be excessive.
  I'll take your 9, and raise you to 26.
  3.14159265358979323846264338...
  
  If you want to bump it up to 29 digits (the next digits being 327, not rounded), there's always this old gem

Ladies and gentlemen,
Hobos and tramps,
Crosseyed mosquitoes
And bowlegged ants:
I come before you to stand behind you
To tell you something I know nothing about.
The price is free, so pay at the door.
There are plenty of seats, so sit on the floor.
One bright morning in the middle of the night
Two dead boys got into a fight.
Back to back they faced each other,
Took out their swords and shot one another.
A deaf policeman heard the noise
And came and killed the two dead boys.
If you don’t believe me, ask the blind man;
He saw everything.
Memorized while bored in elementary school

The lyrics to Spell it Out by The Lonely Island

In 6th grade we could get some bonus point on our final exam for knowing how to spell pneumonoultramicroscopicsilicovolcanoconiosis (which isn't actually that hard to spell, just long) and I've never forgotten how.

A A Am Ae Ae A Ae Ae As Arum Is Is
And also Sum es est sumus estis sunt
I studied it in highschool and have a degree in science.

And they ask you how are you, and you just have to say that you’re fine when you’re not really fine, but you just can’t get into it because they would never understand.
I’m still waiting for an appropriate moment to say it aloud.

    
0 for i=1to520: r=rnd(1): printchr$(r+109.5);:
next i: c=r*16: poke53281,c: poke53280,c:
poke646,c*9: goto

Area codes. Given most of the original US/Canada area codes, I can tell you where it is.

My parents now defunct landline number.
- I still remember my landline number from when I was 4 and there were only 5 digits. It makes me feel extremely old.

One dull day, in the middle of the night, Two dead boys got up to fight. Back to back they faced each other, drew their swords and shot each other. A deaf policeman heard the noise and went and shot those two dead boys. If you don't believe my lie is true, ask the blind man, he saw it too.

Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto.
I was kind of a space cadet, so I never learned the planets by mnemonic, just by remembering their names.
Now Pluto's been demoted (but not in my heart 💔), and I never actually need to refer to my list of planets anyway :\
- Pluto will always be a planet!!!
  
  ♥️

ι.ε.ε.σ.κ. (Greek letters)
It's the initials of some words from a class about home economics at school. I thought it would help me memorize them, but almost immediatly decided not to memorize them that way, because I feared that if I kept doing it for such unimportant things I'd soon fill up the space on my brain or at least it would become less effective of a memorizing mechanism over time.
Well, thought a bit too hard about not doing so I ended up remembering the initials. Until some time ago I think I event remembered the whole words.