Later this week I’ll celebrate another birthday. It will be one of those “decade” birthdays, where the first digit in your age moves up a notch and the last digit in your age cycles to zero again.

Let’s face it: decade birthdays are somewhat annoying. Just because our culture long ago settled on a “base 10” number system — presumably because the ancient Egyptians realized that we’ve got ten fingers on our hands, and chose to build mathematics around the concept of ten as the path of least resistance — doesn’t mean there should be any special significance to celebrating a birthday when your new age divided by ten produces a whole number rather than a fraction. It’s just another year added to the ledger, and the turn of the calendar page doesn’t mean you should feel or act any different.

And yet, everybody treats the “decade” birthdays as if they are some hugely significant milestones. Sure, 13 and 18 and 21 have their own special elements, but the decade birthdays can actually define you as a person. Suddenly you’re “in your twenties” or “in your thirties,” and people expect you to behave in a certain way. And as those decades creep upward, the age-related expectations tend to become even more fixed.

So I’ve got another decade birthday coming up. So what? The decimal system doesn’t define me. In fact, I’m going to pretend that we’ve got a base 8 culture and ignore it.