D.K.R.K.
Don't Keep Random Keys. If you don't know where the key goes, don't keep it. It's just a waste of time and space.
I found a key. I kept it. Now it's just sitting in my pocket. Useless.
My brother found a key. He kept it. Now he's got a key with no lock. Ridiculous.
You found a key. You kept it. Now you're just holding a paper clip. Pathetic.