For me it's a habit formed as a young boy because my uncle taught me that while I'm asleep Satan shits in my mouth and if you eat before brushing your teeth you're eating Satan shit. True story.
I dunno, if I gag while brushing and I've recently eaten, I'll throw up. Also I don't usually eat for several hours after waking up, it's coffee then late lunch then dinner, so waiting to brush doesn't make a lot of sense.
Because I wouldn't consider "Satan shitting in your mouth" to be any sort of valuable knowledge. So I'm curious what other screwed up things he tried to pass off as knowledge.
It's childish shit man. It's funny shit you tell kids so they'll do what you need them to do, like brush their teeth. I have fond memories of the man. He had a good sense of humor.
I don't know what other funny stuff he taught me. He was pretty religious, he wanted me to be but I wasn't.