Right. As if half marathons are supposed to be something in a wholly different universe than running a mile a day? It's great exercise, and I personally wouldn't want to do more than a half marathon, since the health benefits seem to be kind of limited and injury rates start creeping up. But someone who runs a mile a day is in reasonable shape, and the distance in fitness from a mile a day to running a half marathon isn't so great.

In contrast, I know people who do ultramarathons, running 50+ miles at a stretch, and I simply cannot imagine it. I'm impressed with people who do: the training, the determination. You can't just wing that. You can't do it on a whim. A half marathon you can do a half-ass job preparing for, and it won't be fun, and you'll feel bad afterward, but it'll be doable. Different categories.