I only wrote down 4 things regarding games while I was a kid:
1) Kirby's Dream Land 2
You have to combine the fish buddy with the electricity power up, to get a light bulb attack. There was a dark room where you had to use that to destroy some blocks in the middle and "read" the icons hidden behind them. Each icon represented a power up. Then at a later part of the stage you were constantly given a choice of power ups and you had to choose the correct ones in order to get the final rainbow drop.
So anyway, I noted down that sequence of power ups on the back of the manual
2) Sonic 2
When I was a kid I was a wuss and couldn't beat Mecha Sonic on the death egg. I would only hit him with a spin dash when he would be moving while not in ball form. Today I just pound him while he's standing and I finish him off in like 25-30 seconds.
Anyway, since I wasn't good enough back then to jump into his face while not hitting the spikes on his back, I had written down on paper his entire attack pattern till I got an 8th hit.
3) Toy Story on the Mega Drive
I just noted down the level select codes.
The weird thing is that I never bothered writing down Megaman Willy's Revenge codes down. I just always expected myself to be able to remember them. That or I was too lazy to make a grid
(it's kind of big so I'll just leave a link...)
