"The Wonder Bread Years" is not a play, which explains its shortfall but also its pleasures. A one-man reminiscence about a period -- approximately a couple of decades from the late '50s through the '70s -- it reaches out to enfold the willing audience in nostalgia.

For this, specific dates are best avoided, to create more hooks to catch us. Conversely, specific details are essential, whether about Silly Putty, Hula Hoops or other trivia of our youth. The simple mention of these sets off little audience wildfires of giggles, in one part of the audience for Slinkies, in another for Tony the Tiger. And of course there are plenty of era-nonspecific childhood debris such as Crayola and Silly Putty.

Clearly we cherish these memory triggers, which take us back to a particular childhood time. But we also love the generic quality, so that the specificity of one half-decade can stand in for that of others. As the author-narrator says, whether we're 65 or 25, we were all once 5.

Personally, he had me with the memory, not visited in half a century, of freezing things on toothpicks in ice cube trays. For others, it seemed to be dropping clothes pins into glass milk bottles -- even if you didn't do it, you more or less did. I guess he had most people from the start, when we stood to join in the Pledge of Allegiance.

Credit writer Pat Hazell, of the high school class of 1979 -- but more important, as he noted in a PG interview with Sam Bennett, from the middle both of the country (Nebraska) and of six siblings. So his childhood references extend to those of his older and younger siblings, overlapping "both boomers' (Howdy Doody, Lawn Darts, Spam) and Gen Xers' (Sesame Street, Big Wheels, Pop Rocks)."

Credit also Hazell's considerable experience in harvesting the comic potential of these memories as a stand-up comic, playwright ("Bunk Bed Brothers," which gave birth to TV's "American Pie") and writer for "Seinfeld."

But credit especially his current delivery system, actor John Mueller, who has the specific talent of not seeming to be an actor at all, which is appropriate enough for a 110-minute evening that is, as I've said, not a play.

Mueller has that earnest, slightly geeky, guy-next-door quality that disarms criticism. I have no idea which of the memories he recycles happen to be his (Hazell is said to personalize the material for each actor), but he totally disappears into a character who, in this case, seems to be him -- a hallmark of very good acting. You could swear the priceless home movies he shows are actually his. He has a disarmingly clunky smile, such that his surprising barbs of wit really sneak up on you.

Surprisingly, and almost breaking his contract to be ordinary, he has real talent on the banjo. But it's a Cap'n Crunch banjo, so that's all right.

"Wonder Bread" isn't a play because there's no conflict, no plot, no real structure or development -- one segment is much like another. That's why, at 110 minutes, including an intermission in which the audience can pursue its nostalgia recall, it feels a shade long.

I don't much care for the set, a cliche of a small-town home. I gather it comes with the show, which City Theatre is hosting, not producing on its own. And I could do without the closing sermonette about the ability of kids to see wonder in the ordinary. Accessing our own inner kids, we already got that point.

But "Wonder Bread" makes no demands, and I have seen it take a heterogeneous audience and bond it in happy laughter.