This morning we discovered that one of the household gnomes had broken the bathroom sink. It wasn't too badly broken, actually, only the little metal piece which raises and lowers the drain stopper. I did wonder how much force it took to shear the end off a 1/4" piece of steel, but neither my contemplation of such issues nor my inquiries of the children ("Which one of you broke the sink in your bathroom?") got me any closer to a working sink stopper.
So off I went to the hardware store. I found the parts I needed (complete with printed instructions on the back) and a tube of plumber's putty. Then I pulled the old parts out and replaced them.
I should probably mention that this is a first on several levels: My first plumbing job, my first significant repair to anything broken in our house, and the first time I fixed something completely and totally on the same day I started. It is also notable for what didn't happen: No 2nd trip to the hardware store, no hospital ER trip, no leaks, and no leftover parts.