I remember in first or second grade when I realized that, when I made a mistake, I didn't have to erase the whole word and I could just erase the part I messed up.
Oooh, the password thing totally gets me. Usually I have to start over because I don't know where I messed up. I type them in too damn fast and by the time the little brain part that's monitoring things says, "Hey, that one key was wrong," I'm ten characters beyond and wasn't counting anyway, so I have to start over.
Yeah I might be a weirdo. I count the dots to where I was still comfortable assuming the password was correct until, delete to there, and finish the password again and pretty much always works.