I'm not sure what it is, maybe an innate desire to be a part of something or an innate desire to help others, For all I know it may be the upbringing or nurturing side of the philosophical question. But for me it seems rewarding to help others. (maybe why I got a teaching degree). But it does help to find others of like mind who will help with no need for compensation, other than a "thanks for the help". My day job these days is helping golfers repair their broken products for $. But helping bike riders learn is more rewarding for me. Just some ramblings and a guess as to why I participate. Smiles, MH