It only takes one.
One time. One run. One race.
When you haven't done something, it seems so daunting. If you haven't ever run before, it may seem like the most difficult thing ever. If you've never run a 10K before, that could seem like a monstrous obstacle.
But once you get out there and do it, it suddenly doesn't seem as bad.
Running your second 10K is not as tough mentally as the first one. And I suspect my second half-marathon won't be as rough as the first one.
See, you give yourself confidence by doing something just once. If you don't think you can six miles, try it and you might surprise yourself. Once that first barrier is out of the way, the rest will come easily. I ran my first race last June and I'm hooked now. I ran the Mud Run in October and worried tremendously about it but now that I did that one I'm anxiously awaiting the next one, on June 13.
I ran the half in April and I'm looking forward to the next half-marathon. I may run the Long Beach marathon, and if I do I know that the next marathon after that won't seem quite as daunting.
So if you're fretting over a certain distance, a certain run, a race, go out and try it and you might surprise yourself.
It's not as bad as you think. Trust me.