In a few species of birds, the mothers lay their eggs in other birds' nests. The host bird is then left to raise the hatchling along with her own brood.

In North America, the brown-headed cowbird is the most typical species for this kind of behavior. Somewhere along the way, when it sees one hatchling that differs so starkly from the rest of the brood, I suspect the parent bird thinks, "Gosh, Gerald is such a nice boy. And so big and strong too! I wonder where he gets it?"

I can sympathize.

Max is my son, and he is 7 years old. Max is a very athletic child. Team sports aren't really his thing though. Instead, I have fathered a Ninja Warrior.

To be clear, I do not suspect in any way that Max is not the biological product of my wife and I. It just seems like it.

For example, this summer Max has decided to forgo baseball and instead focus on competitive races and obstacle courses. The highlight of his summer will be a weeklong rock climbing camp in Bloomington. He has calluses on his hands from climbing ropes, trees, furniture, walls, chains, and anything else vertical and unsupervised.

Never in my life have I had calluses on my hands. That sounds terrible.

Within the last month, Max has been in a Fun Run (an oxymoron), a two mile obstacle course run called Spartan Race Kids, a 1.5 Mud Run (not an oxymoron at all, there was plenty of both) with his dear father, and a 5K Color Run.

He has loved it all. He has more planned for the summer. When we finished the Mud Run, he made a point to tell me that he was proud of me.

Ugh.

Max is the child of two librarians, and two relatively unathletic people in general. Sports aren't our thing. And sports that involve even a little terror, exhaustion and/or calluses are just awful. And now they are a part of our life.

As a teenager, there was a name for someone who talked about their muscles. There was a name for someone who ran around shirtless most of the time. There was a name for someone who bragged about how many pushups he could do, and then ripped off a couple more one-handed, just to make a point. That name was Meathead.

Now that person has a different name. Now I just call him My Guy.