We played Pokemon and Wolfenstein 3D on our FX-9860Gll during high school math class (instead of doing maths).
I’m regularly astonished what can be pulled from those little machines.
Even after graduating university, it still sits by my side.
I still have my TI-89 graphing calculator from 20 years ago. Last I checked it still worked. I have fond memories of graphing the Mandelbrot set on a long car ride and writing Palm Pilot-like, OOP-ish programs in math class (before I discovered Java).