Gates and three Lakeside classmates were banned for a summer from a local computer company after they were caught exploiting bugs to grab free machine time. The punishment became a deal: free computer time in exchange for hunting down the system’s bugs.

Handed the job of writing his high school’s class-scheduling program, Gates arranged his own schedule to land in classes with a disproportionate number of girls he found interesting — something he later admitted in a Lakeside commencement speech.

Bill Gates has a published mathematics paper. As a Harvard undergraduate he co-wrote “Bounds for Sorting by Prefix Reversal” (1979) on the “pancake sorting” problem with professor Christos Papadimitriou — and the bound he proved stood as the best known for roughly 30 years.

One of Bill Gates’s own coding credits is DONKEY.BAS, a crude driving game he co-wrote in 1981 (with Neil Konzen) to ship with the first IBM PC. Apple’s Macintosh team later singled it out as an embarrassment.