Hey, high school wasn't a complete waste of time.

I also remember y = mx + b, which would be handy if there were any such thing as linear in the real universe.

That's about it. There was some social stuff, and how to use flash cards to memorize piles of data, and the historical connection: I dropped out of the same school Ronald Reagan graduated from. Also, I got to play politics (a huge learning experience) with the Dixon High School Law Club (I was co-founder, and it was still going strong last I checked a decade later (that was a long time ago) and still not recognized by admin) getting a bridge named after him.

Otherwise, complete waste of time. Glad I only wasted a couple of years.