A few weeks ago, I registered Dan and myself for a Sunday-morning 5K Jingle Bell Run. A friend of mine has a family tradition of doing a Jingle Bell Run in Illinois every December, so I was familiar with how it goes: Everyone shows up in Christmas costumes, wears jingle bells, and generally has a good time while they race the short trail. I've never taken part in it myself but have wanted to, so this year, we decided a West Coast branch would be established. I registered without knowing that the weekend would be one of our busiest in...

