I'm thinking of stealing things from friends and roommates and I don't know why.
Why do you think you want to steal things?
I'm not sure, it's hard to describe. I just get a kick out of it and start laughing when I'm alone with the things I stole.
You have a desire to take things that aren't yours I understand. This is a problem that needs to be halted before you end up in a prison cell when they find out you are behind this terrible theft ring. Put the things back and confess, they would forgive you more now than later after you were caught.
They can't prove it was me, my roommate would say I was home at the time.
If they find the stuff in your room then they will know it's you.