The other day I ran a 10k (with about 26,000 other people). I realize for some, that's not much of an accomplishment, but I hadn't really run at all since my last high school gym class in the mid '90s. And even then, I don't think we ran more than a mile.

In August, when I started using a Couch to 5k app, I couldn't conceive of running for 6 minutes, much less 6 miles. I'm not exactly sure what compelled me to try running (something I've never liked), though maybe it's not a coincidence that I'd seen Zoë Romano speak not long before—running for a few minutes seemed much less daunting compared to her challenge of running the Tour de France.

About a month before the end 10k training, I started thinking about writing a post on my misconceptions about running. I decided to wait to see if I managed to actually finish the race before writing it. Now that I've gotten around to it, I see they weren't so much misconceptions as excuses.

So, here they are, my top five excuses for not running, presented in countdown format in honor of Letterman's retirement.

5. I need special clothes/shoes

I wouldn't recommend trying to run in wingtips, but, if you're like me, you likely have some kind of sneakers lying around. I ended up getting some new shoes after a couple weeks, but the pair I had already were more than enough to get me started.

4. I'm just not a runner

This is probably true, in the sense that I'm not going to win any races, but I can accumulate the health benefits of semi-rapidly putting one foot in front of the other repeatedly for tens of minutes at a time.

3. They're all gonna laugh at you

Running (or, as like like to call it "running") takes enough effort that I can't say it's been at all embarrasing. And as far as I can tell, I'm the only one who cares how fast I run.

2. I don't have time

This is the mother of all excuses, of course, but the truth, as always, is that we all make time for things we want to do.

1. I'll do it tomorrow

Hey, guess what, Tony? If you do it today, you won't have to do it tomorrow!