I sat in on a session where someone suggested John Hartford's Steam Powered Aereoplane, and it was played, with me struggling along on guitar. I later posted a request for chords on Mudcat, had some suggestions, then posted what I came up with, though wrong.
I printed a copy of this wrong chord pattern and took it to another jam, where someone else suggested the song. The woman next to me starts leafing through a notebook, and I show her my copy of the song saying "I have this and it's close, but not exactly right." She finds her page, and says "well, this guy seems to have worked it out", and there in front of my eyes is a printout of my post from Mudcat. A Twilight Zone moment, and a realization that what we do here, for better or worse, is often an act of archiving, preserving, and instructing, which is taken seriously by people we may never meet. Or who may end up sitting right next to us.