In our internal Q&A system I make it a point to describe what the resolution was, even when the mistake is something obvious or embarrassing that I did. I like to think my legacy will be leaving several dozen self-answered questions on common problems that other developers didn't feel the need to type up.
One of my favorites is finding such a post, getting hopeful to find an answer, and then realizing it was me who wrote the post years and years ago.
I once was helping a coworker with a problem and asked about it on a related forum. Later that week he came over and told me how he found a forum where someone else who had the same problem, and their username looked a lot like my name…