I'm probably supposed to know a lot about my car, but I don't. I know almost nothing about it. I'm diligent about its oil changes and its regular maintenance, but that's it. I have no knowledge of its deeper secrets, and I'm completely fine with this.

The scene was this: Saturday. Four-thirty in the morning. Driving to San Francisco. Right rear tire; a total blow-out. Unbelievably loud. Like a helicopter hovering directly overhead. I pulled over to the shoulder.

In the span of thirty seconds I decided I did not want to change the tire. My reason? I'd get dirty. Oh, and it smelled really bad down there. More than burning rubber, it smelt a little like shit, and I was at a loss to understand why. I didn't dwell on it.

I called directory assistance and asked for a towing company. The first one was answered by an impatient woman who could not contain her incredulity that I didn't know, in plain language, precisely where I was in this great state of ours.

"I'm really sorry, but all I know is that I'm on Interstate eighty heading west to San Francisco. Across the highway is a Freightliner distributorship."

I offered to give her very precise coordinates via the GPS unit I stow in my glove compartment (another story) but the words longitude, latitude, and of course GPS were just funny-talk to her. She asked me again to tell her what the last exit was that I'd passed, and I said that she could ask me a third time, but I'd still be unable to say.

She started to ramble some exits off for me, as if that might jog a memory she assumed I possessed.

Trying to be a little funny, I said, "You know, I drive this route so often, I never think today could be the day I'll need to know every exit by heart." I said I hadn't planned on sitting by the side of the road with a blow-out. She didn't find me funny.

She put me on hold a few times. Other calls came in, and mine was a difficult nut to crack. My call could wait.

Finally, she said she'd look up Freightliner in the phone book to get an idea where I was. I thanked her for that. She returned and told me she'd solved the mystery, knew exactly where I was, and went on to tell me a little story about how she'd seen those Freightliners by the side of the highway one time when she was going to the airport to pick up her mother.

She called her driver and after sitting on hold for another ten minutes she returned and said her driver didn't feel like going on a "wild goose chase" to "God only knows where" looking for me.

"Can you recommend another towing company?" She gave me a number and I thanked her for that.

I woke the other tow truck driver from a deep slumber. It's his own rig and his own company. He swore he'd only been dozing, and I didn't argue the point. Forty minutes later he was lying on the ground looking for the best spot to position the jack.

I did my bit by standing hunched over, hands on my knees, trying to to look ready to help or offer up anecdotes about how it felt when it happened, or the fact that I'd just had the car in for its thirty-thousand mile service.

I'll admit to feeling a little humiliated by how easy he made it seem. Piece of cake. For him.

So there was no trip to the city for me this weekend. I drove home on the spare. Made my appointment with Toyota, and watched Martha Stewart on television.

That's what I was supposed to do, right?