You dont have to be a genius nor do you need any special methods to store your private keys. Pen and paper is fine.
Thats what I learnt from watching Andreas. Heres the link of the video if you need it:
https://youtu.be/vt-zXEsJ61UThat's goo but way too hard since we need to fill it up anytime, I prefer just a protected notes or excel wherein only me can access saving at my phone and a qr code in my physical wallet, no one knows what it is it since closes people did'nt know yet I deal with crypto.