I always have to explain my knees. There’s a keloid on my left, an irregular pink mound that started as an angry scar and just kept growing, the last evidence of my fall from a bike at age 13 (that, and the fact that I haven’t successfully ridden a bike in the six years since then). Skinny Asian female, about five feet three inches, has a birthmark on her smallest toe and a disfigured left knee.

“What’s that?” People will ask, eyes flickering nervously over the growth. No mention, of course, of my cute skirt.

“It’s a keloid,” I begin to explain, clapping one hand over the damn’d spot and clutching my kneecap. By the end of the story — all right, end of the sentence — their eyes are more riveted than ever on my poor little joint and their lips are pursed just tightly enough to keep the “T.M.I.” from coming out.

(You’re probably right to be grossed out: Plug “keloid” into Wikipedia, scroll down to the photos of those unfortunate people who have become clinical examples for millions to see, and you’ll see what I mean. For the record, though, my keloid rises only a couple of millimeters, and it’s no bigger than a quarter.)

Too much information? Maybe, but as with most T.M.I. situations, maybe my cringing audience also just don’t want to imagine the same thing happening to their knees.

If the classic “Head, Shoulders, Knees and Toes” is any indication, our knobbly lower joints are one of our bodies’ four greatest landmarks. Let’s face it; we’ve got a fascination with our knees for the same reason we’re fascinated by that reality show contestant they clearly allowed on-screen just to trip up the other ones. They’re a calamity waiting to happen.

Among athletes and arthritis sufferers, knees are the first to go. Among the rest of us, knees hit the pavement first when we skid on rollerblades or tumble off bikes. We fall to our knees. We’re weak at the knees. We’re brought to our knees. We go down on bended knee. We’re knee-deep in vulnerable, knobbly knock-knees. And we’re afraid of exposing them to the elements.

So maybe it comes as a little bit of a relief that the temperature is dropping and we all get to cover up our knees.

I’m watching my own knees disappear with a mixture of relief and resignation. There won’t be any awkward comments about my keloid, but neither will I have an automatic conversation starter or proof that my knees have been through more than yours.

Bust out the opaque tights and the cords, people, because the knees are retiring, and you won’t see them again until springtime.

Good thing cankles are always in season.