As I wandered into a greasy spoon and took a seat at the counter, I was contemplating, as the Stones sang, what a drag it is getting old. A waitress standing a few feet away, unmoored from customers at the moment, sang along to an Elvis Presley song from the Fifties playing on the jukebox. As I listened, I realized she knew every word.

The waitress was about 20. Elvis had been dead more years than she had been alive. How, I wondered, did she know the words to an Elvis song? And not to just any Elvis song, but one from the Fifties?

I don't know the words to, say, a Count Basie song. Okay, Count Basie songs don't have words. The point is that this girl - and, yes, she seemed to me just that, a girl - was extraordinarily familiar with a song that was so ancient as to be practically Biblical. (And Elvis begot The Beatles, and The Beatles begot the English Invasion, and the English Invasion begot hair bands, and hair bands begot punk, and punk begot grunge, and grunge begot thrash-metal-indie-ska-hip-hop.) At 20, I did not possess the same effortless knowledge of my parents' music.

We started chatting. "I love classic rock," she said. "Led Zeppelin. All that stuff. Everybody in my generation really likes that stuff."

The next day, I stopped to check out a poster sale. The posters taped to the outside walls, presumably to entice customers, weren't of anything having to do with the current generation. One was of Muhammad Ali glowering over a flat-on-his-back Sonny Liston. Another was of Jim Morrison. A third depicted Jimi Hendrix coaxing fire from his guitar. The only poster remotely related to current times showed Kurt Cobain in performance.

What, I wondered, am I to make of this?

Is there a generation gap or isn't there?