Reminds me of highschool math. At some point you needed a graphical calculator, you could load programs into them but that required hooking them up to a computer with a crazy expensive data cable. So I found a schematic, ordered the components for a fraction of that price and learned to solder. It looked ugly AF, but it worked. Next step I wrote a program containing the formula’s I needed, uploaded it and installed a program which hid your program menu until you pressed a certain key combination. It could even simulate a hard reset, as you could get spot-checked and asked to do just that.

I could also have memorised the formula’s, but that wouldn’t have been fun. And unlike all those formula’s I still use my soldering and programming skills. 😋