The most idiotic thing that I have done for a long time... Fell off a stool* and gave myself the most painful bruise I've ever had (about 6 inches diameter). I couldn't sleep well and, in fact, it hurt to walk - I had a limp.
I was painting the living room and wanted to reach the top of the wall so that I could paint a neat seam between the wall and ceiling.
On the bright side, I'm almost all better now and it's only been two weeks! Oh, and my living room looks very nice.
* The stool was placed on a chair; so, technically speaking, I feel off of a chair and a stool.
* I fell off more than once.