What's this one, he asks, holding out a rock. What's this one? And what's this one, he asks, picking up a clod of dirt, which not being a rock in the strictest sense crumbles through his imaginary fingers. Oh, he says.

My answers are variations of That's a gray one or That's a small one because I know nothing about rocks and I'm not a fan of I don't know.

This one must be sandstone, my imaginary son says, and I say Then sandstone it shall be.

Questions my imaginary son asked last week: Where does my breath go when it leaves me? Where is Wyoming? Will I melt if I get hot? What is Naugahyde?

The last one he needs for a poem he's writing in his imaginary writing circle at school. His poem is called "Don't Pee on my Naugahyde Heart please." I don't think my imaginary son is destined to be a poet. But I might be wrong.

Questions this week: What is green? What if the oceans were ketchup? (biggest smile ever) Are rocks alive?

I'm ashamed to say I had to look that last one up. Turns out rocks, though they've been around for millions of years, are inorganic—like air and water. To exist is not to live, I say to my imaginary son. We share a laugh because we kind of understand what I mean. Ask your imaginary teacher I say finally, and he rolls his imaginary eyes.

When I was in fourth grade, I was obsessed with mazes, ferns, those bags of worthless stamps you get for a dollar from Boys' Life, with Chopin runs and Jesus.

My imaginary son wants to learn how to swim. When he asks if the swimming pool can be filled with shadow, ketchup or spring because they're cool and he's afraid of getting hot, I'm reminded that I have an obligation to prepare my imaginary son for a life far fuller than a real one, that he'll need to know how to swim in his oceans.

My imaginary son's imaginary room is filled to the ceiling with imaginary rocks, each one labeled. Most are limestone, but there is the odd obsidian, one tagged "igneous ignoramus." Where did you learn that word? I ask. School, he says. Did someone say it to you? I ask. Because you are anything but an ignoramus. This one's metamorphic, he says and holds out a rock. It was two thousand degrees, but it's cold now. People are stupid, I say. Ignore them.

Questions today: Am I a dancer? Can I die? Do rocks die?

My imaginary son looks to me as if I should know the answer to all these infuriating questions, and I do—though I don't want to. Rocks, I say, can't die, but I don't say, Because they never lived.