I am Surprised by My Own Strength

So about a month ago I went to empty the incense holder we keep in the bathroom. It's marble or something similar; we bought it at an Indian store on University Ave. some time last year. Anyway, it was full of ash, so I carried it over to the trashcan, tipped it upside down, and tapped the back of it with my finger. Not, as it was later alleged, against the edge of the trashcan. Just with my finger. It broke in half.

Naturally, this greatly amused my friends, a bunch of whom were in the apartment at the time. When Afshin and our friend Daniel and I hopped a bus to go on a joint grocery-store run a day or two later, they again began ribbing me about the broken incense holder. I explained once again that I emphatically did not smack the marble against the metal trashcan, as that's an obvious no-brainer. I went to demonstrate, using my nail file as a stand-in incense holder. But, since I was sitting close to one of the metal poles on the bus—and my file was of the reusable glass variety—Afshin foresaw danger and laughingly warned me, "Hey, don't break that, too."
I got cranky. (Oh, why must bad things happen when I get cranky?) "I won't break it," I snapped. "I'm not going to hit it on the pole. I'm showing you what I did with the incense holder." I tapped the file with my finger—again, without using great force, firmly but not violently. The file broke in two.

Daniel and Afshin burst out laughing. I let loose with a stream of obscenities. Most of the other passengers noticeably suppressed laughter. I think I threatened to stab Afshin with the pointy part of the file, but I can't swear to it. Possibly Daniel, too.
However, I ultimately repressed my homicidal urges and, later, once back at home, surveyed the damage I'd wrought.

My, but that's a lot of destruction for one so small.

Oh, I did buy a new file, in case you were wondering. I have yet to replace the incense holder.