Remember PIN numbers easier
It has happened to everyone before; You stand in front of the bank and the PIN number is just not rememberable. Because this happens to me more often, I thought about how you could carry the number with you, without running the risk that a stranger can take them away or spy on me.
Take: numbers from 1-9 and the 0. Then give each number a color that always stays for that number. So you can paint colored patterns with funny patterns on a piece of paper and no one knows what to do with it. You could also crochet a colored bracelet or sew a colorful scarf in the required colors. So you can always carry the number inconspicuously.
