Aging rock stars, concertgoer reunite for a revealing encore. (Commentary).

ROCK 'n' roll never forgets. That's what Bob Seger said. At least I think it was Bob Seger. I forget.

Anyhow, last week, I tested Bob's theory by attending my first rock concert in years. The band was Crosby, Stills, Nash and Young, a hugely popular group back in the late '60s and early '70s.

Now, Crosby, Stills and Nash are no longer young. Even Young is not young. They have not had a hit in years.

Just the same, like many bands from the baby boomers' heyday (and only a baby boomer would use the word "heyday"), Cros-by, Stills, Nash and Young find themselves in demand by an aging audience that:

1) Can finally afford a ticket.

2) Can't understand Ja Rule.

3) Desperately wants to feel hip, even though we now wear pants with elastic waistbands.

Not that the boys in the band are doing Vic Tanny ads. David Crosby has a belly you could rub for luck. Graham Nash's hair is white. Neil Young has long hair, but only on the sides, which is why he wears a hat. Stills' hair is ... um ... wait ...

Which one is Stills?

Anyhow, here they were, Crosby, Stills, Nash and Young, performing at the Palace of Auburn Hills (Michigan), a wonderful place to see a concert. There are so many bathrooms! And so many concession stands...

Ah. You see? None of this used to matter at rock concerts. What used to matter at rock concerts was how close we got to the stage, how close we got to our dates, and how long the band was playing. We wanted three-hour concerts. Four hours! Five hours!

Last week, by CSNY's fourth song, I was looking at my watch thinking, "You know, if we left now, we'd beat all the traffic ..."

Here are four ways you know you're getting old at a rock concert:

1) When fans leap to their feet, you stay seated, trying to see between the bodies.

2) Beach balls are really annoying.

3) You get really mad when the band plays new songs, because it means you have to stay longer to hear the old ones.

4) "This Diet Coke cost FOUR BUCKS!"

Also, you find yourself singing along and suddenly, you ask, "What the hell does THAT mean?"

I did this last week with CSNY, while merrily joining in during "Suite: Judy Blue Eyes," a song that lasts about 74 minutes and has always been a favorite of mine, even though any song that has a colon in the title should make you wonder.

Anyhow, there I was, belting out the lyrics:

Chestnut brown canaries
Ruby-throated sparrows
Sing the song, don't be long
Thrill me to the maaaar-row!

Huh?

For one thing, I have never seen a sparrow's throat. And by "marrow," do we mean the bone kind or the "other word for tomorrow" kind?

See? We never asked these questions before. You know that song "Our House"? I confess, when the band sang, "Our house, is a very, very, very fine house," I wondered how much they could get for it.

And when Neil Young sang:

Old man take a look at my life
I'm a lot like you were ...

I looked at him and thought, who's HE calling old?

And this Diet Coke costs four bucks!

Anyhow, it was a great concert, and I barely had to stand up, in keeping with the spirit of the band, who sat on stools much of the night.

A few times, David Crosby stepped away from the mike and cleared his throat with a loud "accchhhueew," which sounded kind of like my grandpa.

But, hey, that's show biz. As for the big question, what did they do for the encore, I would like to tell you, but I can't.

Rock 'n' roll never forgets. It does, however, like to be in bed by 11.

Mitch Albom is the author of the bestseller "Tuesdays With Morrie."