As for the racing, I do it for myself as well. No weakness in that, anyone in a race is busting their ass. I do enjoy finding out that I've done well for my age group (I'm 41), but I'm really running for myself. I find that knowing that I have a race in the next month or so is great extra motivation for me to get off my rear on the days when I might otherwise pass on a run. As a bonus, the people at a 5k run are super nice and helpful. I've been involved in other competitive sports and I've never seen such a supportive group of competitors. Maybe it's also due to current timing technology, because each racer (unless it's a very low budget event) is timed individually from the moment his/her bib crosses the start to the moment his/her bib crosses the finish line. Oh yeah, have fun.