Earlier today, while I was waiting for files to arrive to test, I wandered into the back bathroom, used the toilet, and noticed that it seemed to be flushing strangely. Upon further inspection, I noticed a little red thing at the bottom of the bowl. I reached in to try to pull it out and found that it was lodged in the tiny hole at the bottom. Hmmm.
So I went and got a pair of tweezers and managed to get it out. When I did, I discovered that it was a gag keycap that daisy_knotwise had given me for Christmas several years ago.