Believe the unbelievable

So what do you believe in that other's don't believe. Do you believe in U.F.O.s? I've not saw any but there must be something else out there somewhere. Do you believe in ghosts? I thought I saw one once. I went into the bathroom and forgot to lock the door behind me so it was left open a little. I thought I saw someone, my sister, walking by the bathroom and into her bedroom (which was apparently haunted at the time, hope not now, I'm in the room now). Then I walked into the room to see her and she wasn't there so I just said to myself "must be that ghost". Or maybe I was just going mad. What do you guys believe in?