I live in a town of about 40,000 people. There is nobody fast here. I think the fastest guys who show up to the local races are like 18:30 5k runners at best, and it falls off quickly so that 3rd place is a like a 19:30 type 5k dude. I'm not truly fast anymore, but I ran ~14:00 in college 12 years ago and still run. I could probably drop a 16:30 or something if I ran a few workouts in the 6 weeks leading up the race.
However, part of me feels like this is silly. What do I have to prove? That I'm better than some hobby jogger slow pokes in Smalltown, USA? Yet part of me wants to just to make a mini statement. People know I run, but only my close friends know I ran in college and was decent once upon a time... Having conflicting feelings about the whole thing.