Ahh hell. How about another key story.
A couple weeks back, I was a little behind schedule to go to work. Unfortunately, I couldn't find my car keys. Desperate I went and got my spare car keys (that don't have a key to my house), but figured that my roommate would be home when I got back, so I set the alarm and locked the bottom lock. I even sent him a text informing him of this. Being the Christmas holidays, I got off two hours early, and returned home, to find my front door locked. I had to call him, and found that he went out with a mutual friend as he didn't expect be back for another two hours. Luckily, they were only a few miles away, but it still sucked that I had wait outside even after taking precautions. It wouldn't have happened if I had my keys, which turned out to have been under my nose the entire time.