On Saturday I will turn 40 years old. I am utterly at peace with that fact, that number, that arrival.

People get deep in their heads about the first digit of their age, spinning out and developing elaborate defense mechanisms when it invariably changes every decade. It doesn’t help that there is an entire aisle at every greeting card store devoted to “you’re [insert age here]?!” jokes. I’m pretty sure 40 is the starting point for those wisecracks, although given the ruthless way women are taught that 29 is the ideal age I’m guessing there are some even more absurd “you’re 30?!” cards in the mix as well.

But I roundly reject all of that insufferable, reductive, patronizing nonsense. Arriving at the doorstep of a new decade is nothing to be afraid or ashamed of. Life would be meaningless if we could somehow prevent ourselves from aging. The fountain of youth is a crock, a heartless fabrication, and it has been ever since someone conjured it up thousands of years ago.

We grow older. It’s the most fundamental of all human realities.

And thank heavens for impermanence. After all, the inexorable passage of time is the very thing that carves out the narrative arc of our lives. Without that progression — and yes, without that gradual decay — every timeline would just be a flat, dull, straight, endless line pointing straight into oblivion.

Just ask a vampire: Immortality is nothing less than a curse. Aging gracefully (and gratefully) is where it’s at. The chance to shuffle around in this mortal coil for the long, but limited, span of a lifetime is nothing less than a gift.

And make no mistake: 40 is whatever you want it to be. Many choose to think of it as their twilight. The beginning of a sort of hibernation for their contentment, their physical vitality, or even their happiness.

For me, it’s a breaking dawn.