Duh! What was I thinking

That's my right hand with an impressive bruise on it. It's red now but a day ago it was blue and black.
Was it the result of an abusive spouse? A fight? A snake bite? I'm rather ashamed to admit the cause of that bruise.

See, the door in my room has a gap at the bottom. To prevent bugs and such from entering my room, I used a piece of wood to close that gap. Two days ago my young energetic niece accidentally knocked that wood piece off from its slot. I tried to fit that wood back to its original position. It was an extremely tight fit. After a few attempts to push it in, I used my palm to sort of "hammer" it to place. That wood still refused to slot back into its place after my first few knocks. I gave a few harder tries. By then my hand hurt but I didn't give it much thought. Finally frustrated, I went to take a hammer. A few hard knocks from that hammer and the wood was back in place. Success, at last. It was only a few hours later that I realized my hand was swollen and bruised.

Others plead temporary insanity, I plead temporary stupidity duh ; )