This actually happened to me once too! I awoke one morning my senior year of college to find some random dude I didn't know posted up on my apartment's living room couch. I hadn't thrown a party the night before or anything, and he was fairly apologetic when I woke him up. Something tells me it was a worse experience for him than it was for me. Not the craziest drunken occurrence I've had, but it's up there!