Dear Jason,

As I write this, there are still thirty minutes left in your birthday. Actually, this means that my timing is pretty good, since you were born around 11:30 PM. I'd like to say that was intentional, but that would be a lie, and as I'm always telling you, it's not nice to lie.

It's been a big year for you. You got your first big boy bed in January. You had your first dance recital. You were a "ring bear" at your Auntie's wedding. You got to go to Disneyland for the first time. I wasn't there for that last one because I had to work—sometimes it feels like I miss a lot because of work, but then when I go back and look at the pictures I see that I was actually around for most things. I hope that's true, anyway.

The thing you've most been looking forward to—other than your birthday party, which you've been talking about since October—is your baby sister being born. You talk about it all the time. "I'm going to do that when I'm a big brother," you'll say. Some of your claims are reasonable, like when you say you're going to give your sister kisses and gentle hugs when you're a big brother. Some are less reasonable, like when you say you're going to drive Daddy's car. You're also quite adamant that the name you picked for her—Tinkerbell—is her real name, and you will brook no disagreement. I wonder how long that will stick.

Every day I see you figure out something new—you're growing up faster than I know how to deal with. You already can't wait to be big; I can't help but want you to stay young. Though, I suppose if I'm being honest, I'll be OK with you growing up if it means fewer tantrums. (Maybe in a year I'll be laughing at myself having written that.) Well, I suppose I have to be OK with it either way.

I think a lot about your future, especially about how it'll be for you once your sister arrives. I think you'll be a good brother, but then I think it might be kind of hard for you sometimes, too. I know it was hard for me sometimes—you can ask Uncle Karl about that when you get older, I'm sure he'll have plenty of stories for you. Sometimes when I think about what we're taking away from you by having another baby it makes me sad, but my hope is that in the long run we'll be giving you more than you lose. All I can tell you is that for Mommy and me, having siblings has been one of the best and most important parts of our lives. I hope you feel that way, too.

You're asleep right now, which is good because it's late and you had a big day with Mommy at Legoland. I wasn't there for that, but I will be there when we go to Disneyland this weekend, and I'm really looking forward to seeing how happy you're going to be. You and me, kiddo, we're going to have some good times.

Happy birthday, buddy. I love you.

Soundtrack: "Wavy Glass," by Podington Bear