For once the Derbs had nothing scheduled for July Fourth. At least Mom, Dad, and son didn’t. Daughter was at friend’s barbecue. Dad: “Let’s go for a drive out east” [i.e. on Long Island, where we live]. “We’ll go to Montauk!” [i.e. at the tippety-tip-tip of Long Island’s south fork.]

Now, it happens that we have an extra car. A friend of mine lives in New York City and owns a car, which he parks on the street. That’s enough of a chore when you’re around to look after the car. Our friend, however, wanted to go away for a month’s mountain biking in the West. Could he please leave his car in our driveway out here in the ‘burbs? We’d be welcome to drive it — fact, he’d appreciate that, holding as he does the common belief that cars “like” to be driven.

The car is a 2002 BMW. Just to show you where we’re headed here, the Derb family cars are (a) a 1993 Mercury Topaz, known affectionately as Old Faithful, and (b) a 1997 Chevy Malibu, known by several epithets, none of them suitable for reproduction on a genteel website.

So of course we decided to take the Beemer. Couple of hours later we are zooming along Sunrise Highway fifty-something miles from home, headed to Montauk. I’m enjoying the Beemer, murmuring “Eat my dust, loser” — though only under my breath, mind — to vehicles we pass.

That, of course, was hubris, and stirred the attention of Nemesis. Pretty soon: fuppetuh fuppetuh fuppetuh fuppetuh. I had a flat tire. How often do you get a flat tire nowadays? I haven’t had one for years.

Dad, confident master of the situation: “No prob. I’ll just have to pull over and change the wheel.” I pulled over, got out, opened up the trunk, removed about a quarter ton of my (bachelor) friend’s junk, peeled back the carpet, opened up the spare well. There was the spare tire — just as airless and even more chewed up than the flat I’d just acquired.

The rest of our Fourth was a catalog of misery. Call to AAA. Two-hour wait by roadside. Long discussions with the tow-truck driver (a very patient and helpful fellow, I should say), his GPS, and AAA by phone. No Beemer dealership anywhere near. Fruitless search for a Sears store. (In the thin hope that one would be open late on a holiday afternoon. AAA, by the way, gave us two different addresses for Sears stores, neither of which had a Sears, nor anyone in its neighborhood who had ever heard of a Sears store being thereabouts. Thanks a lot, AAA.)

We ended up leaving the damn Beemer at a service station whose yard the tow-truck driver had a key to. Then we took the train home (which involved riding all the way in to Queens, then all the way out on our home branch line, which of course is a different one). Got home at midnight. Psychic states at that point: Dad in Stoic mode, reciting scraps from “The Vanity of Human Wishes” to soothe himself. Mom retreated into oriental fatalism (which has a lot to be said for it), calm but very quiet. Son, who is developing into something of an Eeyore (where on earth does he get that from?), contributing a dash of bitter irony.

No experience is without some redeeming element, mind. During that two-hour wait on the shoulder of Route 27 eastbound, a mile west of exit 63, a car pulled over in front, then backed up to where we were. It was just a family car — old cheap model a bit beaten up: Dad, Mom, child inside. Dad got out. Was there anything he could do to help? he asked. I thanked him and said no, a tow truck was on its way. Did we need a phone? No, I said, thanking him again, we had one. He seemed reluctant to leave without offering us something by way of comfort, so he handed us a bottle of Gatorade. This was a big, rough-looking guy with manual-worker hands, a heavy Hispanic accent and a cheapo old family sedan stopping to help us, while Barbara Streisand, Ron Perelman, Alan Alda, Renée Zellweger, and all the rest of the stinking celebrities zipped past us on the way to their twelve-bedroom Hamptons mansions. Life lessons — I hope my son got it.

Morals of this story: Don’t mess with Nemesis. Treasure the kindness of strangers. If an urban bachelor friend lends you his Beemer, check the spare.