Like most college English 101 teachers, I have suspected my students meet secretly before class and vote unanimously to play dumb for the next 90 minutes, or until Mr. DeLeon breaks out into a Daffy Duck woo-hoo dance, bouncing off the walls and ceiling.

In writing that sentence, I realize that I have revealed myself as a baby boomer. We many. We happy many. We band of sugary breakfast cereal consumers who camped out in front of the TV on Saturday mornings to watch decades-old cartoons unaware that we were being indelibly exposed to classical symphonic music or German opera. We can't dum dee-dee dum-Dum along to the thrilling opening theme of Wagner's Ride of the Valkyrie without chanting, "Kill da wabbit!"

Of course I would never expect my media-branded "millennial" students - aged 18 to 22 - to understand such intimate intergenerational cartoon wefewences. But I do expect someone in that age group to recognize the names of historical or cultural icons like, say, Johnny Carson, Babe Ruth, Frank Rizzo, or Cassius Clay.

I have no idea why I continue to expect my students to have knowledge of such commonplace information from the recent past when all evidence and personal experience point in the opposite direction. Less is the new more. Student familiarity with American history stretches all the way back to 9/11, but not necessarily.

New York Times columnist Frank Bruni wrote on April 8 about his own experience as a college teacher. "Hardly a class goes by when I don't make an allusion that prompts my students to stare at me as if I just dropped in from the Paleozoic era," wrote Bruni, who is 49, and who was talking about his students' reaction to being asked about someone named Jane Fonda.

Bruni teaches at Princeton, but the same generation-based information gap is obvious among the students at the suburban community college where I teach. It's a gap that is not entirely a matter of age differences.

Bruni identified this as "the pronounced narrowness of the cultural terrain" shared by teachers and younger students. In a world of instantly accessible information a few keystrokes away on smartphones, students see no point in training their minds to remember what older people consider the essential canon of the American experience.

This week I gave my freshmen a noncredit quiz to establish some sort of a historical baseline. I provided 20 famous quotations - such as "Give me liberty, or give me death" and "A date which will live in infamy" - and asked them to identify the speaker and the historic context.

The average score was 3 - out of 20. Six students scored lower than 3. The high score was 10. "Let them eat cake" was recognized by only one student. None of them had heard the words, "Give us Barabbas!" Only one recognized "Tramps like us, baby we were born to run" as a song lyric.

The two quotations that were identified correctly the most were, "I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character" and "I did not have sexual relations with that woman."

The narrowness of our shared cultural terrain now seemed more like a sliver. But characteristically, my students demonstrated no dismay in their average of 17 wrong answers out of 20. Millennials don't do "D'oh" when they find out their answers are wrong. There's an eerie disconnect. They don't take their ignorance personally.

And by ignorance I don't mean stupid. These are bright kids. Most of them succeed in appearing confident, self-possessed, in a word, cool. Meanwhile, their teacher is drenched with flop sweats at his failure to ignite their interest in important . . . stuff.

By that I mean sacred stuff I believe every college student should already know by heart. I find their group mask of indifference unnerving. Maybe they know something I don't. Maybe it really doesn't matter, after all. Which makes me recall the last line of a Bruce Springsteen song called "Brilliant Disguise":

God have mercy on the man,

Who doubts what he's sure of.