Tonight I am the exact age that my mother was when she gave birth to me. Up until now, until this day, I thought that she was older when she had had me, as in more of a grownup.

At some point, as a teenager maybe, I asked her when she first felt like a grownup. She told me it wasn’t until she had kids. I birthed my children when I was 27 and 30. I grew up– became a mother– came to embody responsibility and wisdom and sacrifice and love in ways I didn’t understand prior to their arrival. But I didn’t feel like a grownup the way my mom has always been.

My mommy who, since I have known her, just knows how to be the grownup. Who always knows what to do. Who knows the right answers. Who, even in moments of insecurity or uncertainty, embodies those states of being as a grownup– they don’t seem to phase her. She is the most emotionally mature person I know.

There have been a remarkably few times I’ve seen a crack– two that I recall. A vague memory of her upset, throwing a bowl of spaghetti at dinner. My sister and I laughed. And when I was older, a story about being so frustrated trying to find her way somewhere that she turned around and drove hours home. The cognitive dissonance of those stories is jarring– They are so out of place in the image I have of my mom that I sometimes doubt if I remember them correctly.

I know that she probably isn’t as infallible as I see her. I can’t bring myself to delete the “probably” in that sentence– that’s how strong the picture of her is in my mind. I know, realistically, she probably felt just as much like she was flailing her way through early motherhood and everything else as I sometimes do, but even if she didn’t feel like a grownup, as a mother she always acted like the grownup. I aspire to be a mother like that.

I think part of me has held on, thinking my sense of really being a grownup, the way my mom is, would come today. That since I was younger when I had my kids, maybe I just had to wait for today, the day before my thirty-second birthday. Alas, I awoke with the usual patterns of insecurity and impatience still in place.

Still, I think there’s something sacred about today, and it isn’t about it being the day before my birthday. There are milestones we don’t acknowledge routinely in our culture. The day you are the exact same age your parent was when you were born is one of them. Being exactly half the age of your parent. Before today, I was less than half the age of my mother. She had lived more than half of her life before knowing me. Tomorrow, and after, that will be less.

I’m listening to Joni Mitchell’s “Both Sides Now” as I type this and it feels incredibly apt– a way to mark this rite of passage. If it weren’t almost midnight I would light a candle.

When I wrote about my father, my mom told me she wished she could know what I would write about her– that she wished she could read it. Here’s what I’d tell her, simply, if this post doesn’t make it clear:

Today, literally, and every other day in every other way:

I measure my life by yours.