Nate’s teachers write a daily note about the various activities they have in class. One day, under “Math & Science,” it said, “Making a family chart and comparing how many family members live in our house.”

I looked on the wall. Sure enough, there it was. Seven of Nate’s classmates have four people in their household. Three of Nate’s classmates have three people in their household. And Nate himself is the only one with just two people in his household.

Later that month, the class made a Family Tree on one of the walls. Each child was given a round leaf, and they drew a picture of each of their family members. I found Nate’s leaf; there we were. I was green and he was blue.

But I missed an important detail.

You remember my good friends Beth and Paul? Parents of Nate’s friend Jennifer… and the lovely Caroline Sarah, named after my Sarah? The ones who take Nate overnight once a week, so I can visit the pshrink and recapture a few of my marbles? Yes.

Beth quietly pointed out to me that Jennifer’s leaf had five people on it, not four. She told me that when she asked Jennifer who they were, she said, “That’s you, and daddy, Caroline, me, and Nate.”

Nate sees it just as clearly, in his own way. When the class started working on their Mother’s Day books, he told me that he wanted to give his book to Jennifer’s mom. He said it in the same four-year-old, matter-of-fact tone that I imagine Jennifer used: what could be more obvious?

Indeed. Well done, my son.