D.K.R.K.
Don't Keep Random Keys. If you find a key, it's not yours. Don't be a selfish jerk.
I found a key. I kept it. Now I'm the only one who knows where it goes. Selfish much?
My brother found a key. He kept it. Now he's got all the keys and I have none. That's not fair.
You found a key. You kept it. Now you're the reason I have no keys. You're a jerk.