I had three friends several years ago and things went sourish.

Actually, it was just one of them that went sour, but she took the other ones with her, and, well, you know how things are.

Every now and again, I wonder what the tipping point was because we were good friends, or at least (as it turns out) good acquaintances – normal friend things: grilling out at each others’ houses, movies, dinner, that sort of thing.

A week or so ago, I was sitting at the red light at the corner of Piedmont and Monroe, watching the people at the gas station there, coming in and out of the little store, and it all became clear to me.

The day it all went south, we had had a tennis match. It was hotter than the hammered-down hinges of Hell, and we’d been out there from 10 until 4, and we’d all had three-set matches. We were planning to go directly to IKEA afterwards.

On the way there, we stopped at that gas station, and sour girl said, “does anybody want anything from in there?”

I piped up from the back seat and said, “Yes. I’d like a Three Musketeers and a Coke in a can, please, and whatever anybody else wants,” and handed over a twenty.

I remember distinctly that this caused some consternation, because she said, “Seriously? You want something?” and I said, “Well, you asked, and I’m hot and thirsty and a little low.”

She went in and got it, but she was pissy about it.

So I guess it was a courtesy offer and I was supposed to have the courtesy to decline. But I am not a mindreader, despite the fact that I have brown hair and brown eyes.

And anyway, I did not know it was bad manners to take someone up on an offer.

I do not understand courtesy offers and courtesy invitations, though I am aware that people make them all the time. As far as I can tell the people you don’t want to say yes always do.

Now that I’ve figured it all out, I’m right tickled with myself.