My "fun fact" that I always tell is that I got my start by reading the manual of my TI-83+
I spent most of my 9th grade making a stick figure clone of Street Fighter, using TI-BASIC and graphing functions.
Eventually I switched to coding with pencil and paper because the calculator screen can only show you 8 lines at a time. No idea how I made something that could support 2 players playing on the same calculator, all with GOTOs and LABELs.
My favorite optimization of all time was turning their heads into hexagons instead of circles since drawing 6 lines was so much faster.
Same, but it was a TI-84, and the game was tic-tac-toe with a perfect "ai" that would let you enter "number of players: 0" [1]
Mine was a TI-81 and a clone of Scorched Earth with multiplayer, realistic physics, wind, random terrain generation, etc. Used all 2.4kb and every single named variable provided by TI-BASIC on the machine.
For my birthday in 7th grade, I wanted a TI-86 calculator because I could program on it. And maybe because a classmate showed me ASM games on their TI-83+.
In 9th grade, I wrote programs to solve specific kinds of algebra problems while showing the step-by-step "work" on screen. I remember realizing a critical bug in the code during an exam, which surprised me because it worked perfectly for all the homework and study questions.
I ended up spending more time trying to fix it than working on the test! I now realize that it was my first experience with a P1 production bug. In a way, it was my math teacher's fault for not providing sufficient acceptance criteria. I was supposed to learn about polynomials, but I (also) ended up learning about edge cases.