I used to believe my 16-year-old punk son was the one who needed protection from the world—until one icy night, a park bench across the street, and a knock on our door the following morning completely changed the way I saw him.

Throw-up tangled in my hair on picture day. Calls from the school counselor. A broken arm earned by “jumping off the shed, but in a cool way.” If there’s a disaster, chances are I’ve cleaned it up. I have two kids.
Lily is 19, away at college—the honor-roll, student-council, “can we use your essay as an example?” kind of kid.

My …