Ironically I never saw i until my college admissions test for √-1=? and just sat there staring at it, I've got a list of interesting things that surprised the hell out of me that everyone else learned, like that "I before E, except after C, or when sounded as A, as in neighbor or weigh" which I thought was totally cool. I had this old orange algebra book from the 50's or something that I was given to read as a kid and just figured it would be the same crap they taught in high schools. Similarly it was assumed I read enough to know spelling and grammar so I didn't know what a predicate was till my early 20's and I still don't actually know jack about grammatical rules. Informal homeschooling and autodidactism produce some very weird gaps.



The fun of being a 'Mathemagician' I suppose. Once you get a pretty intuitive feel for mid-level math like algebra and calculus you pick up a lot of tricks and rapidly start forgetting a lot of other stuff. Generally I found the best way to teach people stuff was to pretend I was showing them some 'special trick' that let us get around lots of formal boring stuff then show them the formal boring stuff while they assumed they'd just been given the keys to the hidden back gate of the castle of arcana... helped with retention and enthusiasm.