My puzzlement about why "The Nut and the Tire Nuts" is such a popular legend made a lot of people happy - including me.

Now I know why people love to tell it.I'm also gratified when I think of the pleasure I must have given editors, who came up with such headlines as "Flat Joke Drives Folklorist Nutty" and "Am I Nutty, or Just Missing Something?"

And readers were reminded of what one of them called "the best example of clean humor of which I am aware."

It all started back in January, when I expressed my amazement at the long and widespread popularity of this legend, in which a patient at an insane asylum cleverly solves a stranded motorist's problem.

A driver is changing a flat tire in front of an insane asylum when he manages to lose all four of the lug nuts that hold the wheel on. A patient, watching from behind a fence, suggests that the driver should take one nut from each of the other three wheels to fasten the fourth wheel on again, then drive to a service station to replace the lost nuts.

The driver is surprised that a patient in an asylum could so quickly spot a solution. "I thought you were a nut!" he exclaims.

"I may be crazy," the inmate replies, "but I'm not stupid."

Following that punch line, it seems that everyone except me always laughs uproariously. In fact, several readers wrote to say that they laughed aloud when they read the legend in my column, remembering the pleasure they've had in telling it for the past 20 or 30 or even 40 years.

To me, though, the story had always seemed, well, flat. So I asked those readers who find the legend funny to write and tell me why.

Some of you felt that I hadn't given the implications of the plot enough thought - I hadn't seen, for example, that in losing all four lug nuts the driver showed himself to be pretty stupid. Or I hadn't appreciated how fitting it was for the smug driver to be put down by someone he was calling a "nut."

The most telling comment came from a reader who speculated about the nature of the legend's appeal for a couple of pages, then concluded: "But now as I'm writing this, I just reread the story in the newspaper, and it doesn't seem so funny any more."

Another reader suggested, "It must have been your misfortune to hear it originally from a poor storyteller."

That, I thought, is surely the clue. For years I've been reading the story in cold print instead of hearing it in live performance. And I'd forgotten the folklorist's basic rule that "some can tell them, and some can't."

One reader advised me to "next time, try telling this story about a carful of nuclear scientists, Pulitzer Prize winners or TV news anchors."

Or maybe a carful of obtuse folklorists, I might add.

Indeed, another remembered hearing "The Nut and the Tire Nuts" told years ago as the supposedly true experience of an allegedly clever person.

The way this reader heard it, the stranded car held Frank Leahy, the legendary coach of the Notre Dame football team, and four of his assistants.

"The image of the five coaches of the best team in the country groveling in the ditch at nightfall is hilarious," this reader wrote.

I agree, especially since I'm an alumnus of Michigan State myself. The only thing I can think of funnier than a Fighting Irish coach in that predicament is a coach from the University of Michigan or Ohio State.

Thanks for your insights, readers. I can't wait to try out a new, improved version of this legend at my next MSU class reunion.

Jan Harold Brunvand is the author of "The Vanishing Hitchhiker," a collection of urban folklore. Send your questions and urban legends to Prof. Brunvand in care of this newspaper.