By ROBERT WHITCOMB

(Reposting this, with minor changes, to mark commencement season.)

A few months ago, I was chatting with a Dartmouth College classmate about stuff that happened when we were students in 1966-70. I mentioned someone we knew in common and recalled that he was in a certain fraternity. The guy I was talking with, Denis O'Neil, a screenwriter who recently published a part-memoir, part-novel of that period titled Whiplash: How the Vietnam War Rolled a Hand Grenade into the Animal House, politely corrected me; in fact, this person was in another fraternity.

Time has fragmented and mingled stories in my memory and those of others from that era, now almost half a century ago. One could argue that it was a tumultuous era, and thus it's easy to get things scrambled, but most times are tumultuous and transitional. Mr. O'Neil makes much of the stress caused by the fear of being drafted and sent to Southeast Asia, but as bad as that was, it was much worse for young men in World War II. Whatever. We're all the centers of our own universes, and we create narratives to explain ourselves to ourselves and others and to place ourselves in history.

Certainly, the huge size of the Baby Boomer generation, and technological and social changes of its young times, were dramatic, though I would argue that except for improvements in the rights of racial minorities and women, the transformations caused by the Internet (which increasingly looks as if it has made things worse for most people) have been much bigger than "Sixties'' changes.

Still, it's true that in that period one had the distinct sense of living in a discrete and vivid era, which actually began about 1966 and ended about '73. People who lived in the "Roaring Twenties'' -- 1924 to the Great Crash of October 1929 -- told me in "The Sixties'' that they had had a similar sense back in the Coolidge administration.

Youth is intense, and so the memories the now-autumnal people of "The Sixties'' are intense, if sometimes erroneous. From Mr. O'Neil's book, which centers on pranks, fun,  romance (not always fun) and anxiety, you might think that 80 percent of a male undergraduate's time was spent drunk, seeking young women to have sex with and trying to get out of the draft. In fact, even for non-nerds who disliked what we then called "booking'' (has the World Wide Web come up with its own equivalent phrase?)  most of the time was spent going to class, studying and sleeping, not "raging'' (the word for partying).

After all, a lot of students wanted to get into good graduate schools and then fancy jobs. A lot did, and went on to become perhaps the greediest generation in U.S. history. Mr. O'Neil was wise to have constructed his book at least in part as a novel, letting his imagination and telescoping of events provide a better story for the movies, a business he knows very well. If they do make a film of his story, I'd be interested to see how much of it gives a sense of the more humdrum aspects of college life for middle-to-upper-class late adolescents back then.

L.P. Hartley's line "The past is a foreign country: they do things differently there'' is much quoted but people don't do things as differently as they might like to think 50 years later.