When I was a kid, I read a book that described to boys how our bodies would change as we grew up and matured from boys to men — or, if not exactly men, then at least very large boys with beards, deep voices, and an abiding love of grabbing our junk. It wasn’t nearly as interesting (or as frightening) as the companion volume for girls, but it was instructive.

But as informative and helpful as it was, what would be even more informative and helpful is a book that describes what happens as we go from full flower of young manhood to incipient decrepitude.

If there were such a book, it could devote an entire chapter to eyebrows.

What is it with eyebrows, anyway? To begin with, no one really knows what they’re for. I’ve read that they’re like little homegrown sweatbands – that they keep perspiration from running down our foreheads and into our eyes. But clearly, whoever came up with this explanation has never mowed a lawn in Texas. Seriously – you could crank up the Lawn Boy, slap a half-dozen industrial-strength panty liners on your forehead and still be permanently blinded by sweat in about five minutes.

As we age, our bodies change – and usually not for the better. Eyebrows are no exception. I’ve always had a bit of a monobrow; in fact, in that respect I resemble Frida Kahlo, only without the monkeys or the crazy eyes. But the other day I happened to look at myself in the mirror while I was wearing my reading glasses (without the glasses, it just looks like Ernie the Muppet gazing back at me), and I noticed something alarming: not only do my eyebrows touch in the middle, they’re well on their way to meeting in the other direction, too.

It’s true; they’re growing a hairy little land bridge – much like the one that scientists speculate once linked Asia and North America – across my temples and toward my hairline. And it’s not just a couple of hairs – it’s a bunch of them. In fact, if they get much thicker I’ll look like I’m wearing a fur headband, or some sort of weird eye mustache.

Why are they doing this? I like to think that our bodies’ shenanigans have some sort of evolutionary explanation, and that they do the things they do because they help us survive as a species. But what’s the Darwinian explanation for eyebrows that have apparently sent scouts to explore the far reaches of my head? Did they spot the rest of my hair and decide to send emissaries? Do they hope to establish diplomatic relations with my scalp? Is there a book that explains this? No, there is not.

Another thing about my eyebrows – not only are they apparently multiplying and striking out for more promising parts of my head, some of them are also getting longer. And the longer ones aren’t like the regular ones. The regular ones work together, lying down to form pleasing arches over my eyes – sort of like little awnings. Not so the rogues. No, I get out of the shower and these guys are standing up and reaching for my hairline. It looks like they’re doing the Wave. Ever seen a Venus Fly Trap? If my eyebrows were green, that’s what they’d look like.

Of course, at my age, I shouldn’t complain. I still have all my hair, my eyes still work pretty well and most importantly, I still have something that stands up on its own.