When I was little, my sister and I did not get along. At all. We still don’t and I really regret that, but it’s out of my hands now. Anyway, she liked to go through my stuff, so I needed a way to secure it. My bedroom door wouldn’t latch correctly, never mind lock, so I needed a better place to stash things.
Being a big fan of diary-keeping, my diaries were the items I was most concerned with – like government secrets, they could not be allowed to fall into the wrong hands (namely, the hands of my little sister).