Okay, what's the dumbest thing you've ever done that resulted in bodily harm to yourself? Today, I think I did a pretty good one.

Last night, I was down in my basement working on my Control Panel. The bottom part has been cut and I was gluing some support pieces that I can drill the sides into. There is only one door to my basement and that is from inside my house. It's a normal door with a little hook and eye latch up at the top. In my entire time at the house I have NEVER used the latch. EVER. For some reason, when I got down with my woodworking last night I went and latched the door shut. (The latch is at the very top of the door above eye level).
This morning, I had to wake up early to prepare for a work meeting that started at 6:30. So I was up at 4:45, but my mind was still well asleep. I used the bathroom on the first floor and saw that I was out of hand soap. So I had to go downstairs into the basement to get another bottle.
I went to open the door and it wouldn't open. This was puzzling to me. I thought that perhaps it had just gotten stuck. So I tried to open it with a little more force, and it opened very slightly but not all the way. Again, my brain was not yet awake so I just let natural instinct go into effect.
I braced myself and grabbed the doorknob. With as much force as I could muster, I forcefully pulled the door open. I heard a tiny "snap" then WHAM!!! The door opened wide and smacked me right in the nose! I saw a flash of light then felt blood start pouring down out of my nose. It was then that I realized I had latched the door shut the night before, and the tiny "snap" was the hook/eye assembly ripping out of the woodwork. Meanwhile, my nose is pouring out blood and I'm rushing to contain the mess. (Thankfully, the polyurethane finish on the hardwood floors caused the blood to puddle up for easy clean-up).
Running back into the bathroom, I applied some cold water to my nose and noticed that I had a bright red scratch on my upper lip from where the door hit my face, but the nose itself wasn't swollen at all nor was it bruised. So thankfully, I don't believe I broke it. I just severely messed up the inside of the nose and any little scratch to the nose results in copious amounts of blood pouring out.
So here I sit at work with a bright red mark on my upper lip from the door and soreness and 'discomfort' in my nose. If I sneeze, my office looks like the inside of JFK's limo at Deely Plaza.

As time goes by, this gets funnier and funnier to me, but damn. WTF was I thinking?!!!!