Discovering great art, literature, or philosophy later in one’s life offers deep pleasure — deeper, perhaps, than discovering it when one is young.

I’d never even heard of Montesquieu’s The Persian Letters when I read it, about seven years ago, after being directed to it by a French professor. It’s not on most people’s list of the Top 100 books of Western Civ, but it’s a great and deeply penetrating book about cultural relativism and the nature-versus-nurture argument over the differences between the sexes. We learn Montesquieu’s philosophy through his delightful and satirical fictional narrative, in which two Persians, unfamiliar with European customs, describe their travels in France.

Another remarkable late-in-life discovery for me was when I suddenly encountered the work of the Australian painter Sidney Nolan. His brazen and beautiful Ned Kelly paintings (Ned Kelly was a 19th-century Australian outlaw), painted in the 1940s, were the subject of a 1994 exhibition at the Met in New York. Nolan combines a seemingly primitive style with one of the world’s most subtle palettes. His brushwork and color turn even a nothing little bush into a glowing ember.

Last week, I encountered, for the first time, the greatest and most popular standup comic routine ever performed — Abbott and Costello’s “Who’s on First.” Yes, I know — how could I not know about this? All I can say is, I didn’t.

I stumbled onto “Who’s on First” only because I recently taught my husband how to search for movie scenes on YouTube. Although he knew about the Web site and visited it fairly frequently, he didn’t hang out on it the way I do. A movie nut, he was in seventh heaven once I showed him how easy it is to watch clips of a movie simply by typing in a phrase uttered by one of its characters.

“Here, have you seen this?,” he asked, passing the laptop over to me. I watched Bud Abbott and Lou Costello do one of their many film versions of “Who’s on First,” transfixed (like everybody who’s ever seen it) as the words “Who, “What,” “I Don’t Know,” “Why,” “Because,” “Tomorrow.” and “Today” bounced off one another like a pack of ping-pong balls dropped onto the floor. (For the three remaining people in the world who don’t know “Who’s on First,” it’s based on making these interrogative words be the nicknames of the players on a baseball team.)

In the version I watched (the routine varies slightly from version to version — first, a radio routine, then in movies, and finally on television), Abbott and Costello go at it for four minutes and 29 seconds. It’s a stunning bit of memorization, concentration and, above all, timing. No one except a brilliant performer can do it well, and from what I’ve watched, only Bud and Lou could give it the blistering speed and crescendos of frustration it deserves. And although “Who’s on First” lacks Shakespeare’s profundity and plot — it’s a comedic shtick and not a whole play — the routine does have some of the Bard’s fluid way with flummoxing words.

Since last week, I’ve been casually polling my friends, most of them artists. “Have you ever seen ‘Who’s on First’?” I ask. Without exception, they’ve all said yes and expressed surprise that I’d never known of its existence until now. Well, I have at least a partial explanation for why I’d lived unaware of such a supreme bit of popular culture as “Who’s on First”: I’m not a baseball fan and I never liked Abbott and Costello.

Still, discovering “Who’s on First” once again reminds me of how much real art — high, low, and in between — I might be missing because I’m not paying enough attention in my peripheral vision. But now that I’ve found “Who’s on First,” I’ll never let it go.