Dear Thomas Alan:

Somehow, my boy, you are turning three years old. While it is difficult to conceive of the fact that you’ve notched your third trip around the sun–time is truly flying here, buddy–it isn’t too much of a shock to watch you formally enter toddlerhood.

You have fully embodied your boyish personality. There are times in which you become a human wrecking ball, a charge of arms and legs, head bent down, whirling forward without regard or concern. Sometimes the collisions are friendly, other times not so much. I am mostly thankful your head hasn’t grown knotty with all the lumps you’ve pulled up from your noggin.

Even so, you seem at your calmest when you are pushing along a truck or a car, your eyes focused on the transportation of some figurine or block cargo, hands and knees sliding along the wood floor, lips bumble-bee buzzing the tune of a great engine. You’ll drive your rig in laps through the house, our carpet your highway, our entry hall your canyon.

You have a strong posture to match your personality. It isn’t fair to project so much upon you in these early years, but it isn’t all reckless boy for you. There is something more, something solid. One day that will come of good use.

Last week, your grandmother gave us a pair of hair clippers–I’m still not sure if she was only trying to be nice or if she was none too subtly suggesting your head looked like a shaggy dog–and we sat you in the little wooden chair in the bathroom floor, Bob the Builder playing on the iPad to distract you, while we nervously chopped away at your mop. You were very forgiving, and by the end of it, you came out with an okay haircut.

Holding your head in my hands while I worked around your ears with scissors was an intimate experience of sorts. I had never cut anyone’s hair before, so I didn’t know. Touching every inch of your scalp, feeling the remnants of where you collided with a door last week, keeping an eye on the balance of top and bottom, of the symmetry of your face, your neck’s soft nape, the fall of your part, I felt like I got to know you better.

Inside that head of yours is a sensitive and curious brain.

Your mother and I will tell you eventually about the times in which one of us would fuss at you, and you would burst into tears and proclaim, “That hurt my feelings!” It is a remarkable defense, actually. Even though it makes us giggle, it pounds on my heart a little. Not so much for Mama, but I forgive you a little quicker.

Julia, I don’t think, has ever so openly expressed her hurt feelings. She guards her emotions more carefully. You are often careful not to tread too harshly upon them. Watching the two of you play together, tumbling through the cycles of a morning–excitement, compromise, cooperation, boredom, creation, destruction, anger, reconciliation–is among the most fulfilling things for us. You are a good brother to your sister.

Even as you dash into a room and hurtle through its quietude, even as you sometimes pick up the pieces of a game and toss them into the air with a cackle, even then, you’ve taken hold of my heart. When you laugh, my heart leaps with you. When you are sad, it breaks for you in a different way than it breaks for Julia.

I know that sounds obvious–you are not your sister, you are your own–but until you came along, I had only known one dimension of fatherhood. By just showing up, you’ve given me depth and detail I otherwise would have never known.

(And I’m sorry but not sorry to keep bringing up your sister in a letter that’s supposed to be about you. Parenting is a struggle against parity. Something there is that compels you to do for one what you do for the other. Even now, writing this letter to you on your birthday, I am reminded that I wrote one to Julia when she turned three. Forgive me.)

It is quite a treat that you were born on New Year’s Eve, a time of reflection and consideration, a time of anticipation for what’s ahead. In your third year, God willing, you will become an older brother and a middle child. I do not think you will be a quiet middle-kid. Rather, I get the sense you might come to think of the middle as the center.

It’s probably a good fit for you.

Happy birthday, my son.