There are things in life that you think will have a big effect on you or be of great importance, but end up mattering very little. When you’re a kid, the world is full of them: monsters under the bed, what your parents are fixing you for dinner, what colors are your favorite. As you grow up a little bit, the labels on these weighty matters of great import change, but the underlying self-importance that colors them does not. Gone are monsters and in their place are SAT scores, whether that person likes me or likes-likes me, and any number of strong, deeply held opinions on the Star Wars prequels. If you have a kid, you’re exposed to a whole new dimension: breast or bottle, cry-it-out or not, home care or day care?

We go through life wrapping ourselves in these questions, these opinions, that are honestly and passionately held – sometimes for very good reasons – that we think will define us and be the crux on which we pivot.

And often (usually?), they do not.

Over the last decade or so, I’ve gotten to see quite a few friends and family approach and pass the great milestone of turning 40, most of them with grace and charm. Seeing this, and being suitably impressed with my own grace, charm, and emotional control, I lumped the big 4-0 in with all those things that seem like they matter but really don’t. I assured myself that I wouldn’t be sucked in to the cliche of feeling old or over the hill. That 40 is just another number and would feel no different than 39, 38, or any of the ones that came before. I knew that it wasn’t something that needed to be a big deal and that I’d likely sneer at it as my birthday passed me by.

Well, that birthday is tomorrow. I’m down to the last hours of my 30’s. And I am freaking the f*ck out.

We’re told our whole life that 40 is old, aren’t we? It’s the punchline of jokes. We see black party hats, streamers, balloons, and yard signs all emblazoned with giant white numbers, like a taunt. Forty-year-olds are who high schoolers mock and roll their eyes at. At my first job out of college my boss was thirty, which I remember thinking was “old”, and he was a full decade younger than I am today.

I think my problem is that I’m having a hard time de-identifying myself with being a thirty-something. Thirtysomething is a great age to be. Old enough to have learned poise, tact and professionalism, but young enough to be hip, flexible, and capable of reinventing yourself if you need to. Thirtysomethings are still in many ways explorers out on a ship at sea. Eventually, all explorers need to bring the ship in to the shore, find a quiet piece of land, and build a cabin. I feel like someone (me? society? the man?) is telling me I need to do that now. I don’t feel ready.

So, for now, I’ll do the only thing I can. Wrap myself in a warm blanket of friends and family wishing me well and telling me that 40 is one of those things that is no big deal and ultimately doesn’t matter. And maybe I’ll even believe them.

But I’m not done with being an explorer just yet. I’m not content to retire to my cabin and turn my back on the sea. There are things to learn – about the world and myself – and so much good work to do before I’m done. So if I’m going to let myself feel like 40 matters, I’m going to make it matter in the best way I know how. This is the year I commit myself to blending together poise, tact, professionalism, capability, flexibility, and the vigor of youth. I will focus that on doing not what-you’re-supposed-to-do-as-you-get-old, but on the things that I want to do. The things that inspire me. The things that make me feel young.

If I ever do get old, I want it to be with my hand on the tiller and with salt spray on my face.

Onward.