I have a shot that's now titled "If I only had a Rose" as a tip of the hat to the song "If I Only Had a Brain." The first time I printed it, I flipped it. Then, once I'd realized it and tried to redo it, I eventually discovered that the contrast filter I'd written down was not entirely accurate as I'd had two filters in the drawer for that flipped print. I don't want to think about how many pieces of paper got wasted. And to top it off, it's originally a color neg and I decided it looks much better in color.
This did lead to my always leaving the filter drawer open when I'm done to signify I've checked that it's empty - no more double filters.