I ran a marathon last week, and it broke my heart.

"It was hard, but at least I finished," I tell the people I don't know as well. With others, the words "excruciating" and "demoralizing" and "disappointing" might make their way into my answers. But I'm still smiling as I list the reasons why my race was all those things.

I'm not very good at letting people see my grief. I know this because sometimes they've laughed when I've told them about my race, and I'm sure they thought they were laughing with me.

One week ago, I was shivering in shorts and a T-shirt and marveling at the colors in the morning sky. It had been a long week and I knew it would be a hot day, but I had no misgivings, no latent fears that my body might fail me.