The Bard would also have heartily endorsed the international ad slogan that Reebok rolled out nearly a decade ago: “I am what I am.” It is, after all, almost exactly the same as “To be or not to be.”

That’s a trick called diacope, a verbal sandwich of two words or phrases with something else tucked in the middle. And it’s almost guaranteed to give you a memorable line — whether you’re saying “Bond, James Bond” or “Be all you can be,” or “Home, sweet home,” or “Bigger than bigger.”

Even a line like “I am what I am” — which let’s be frank, doesn’t actually mean that much — can enter the public consciousness because of its shape. Shakespeare knew that. If he were around to write a slogan for Walmart, he might come up with something along the lines of the very one the company used for years: “Always low prices. Always.”

Diacope is just one of the figures of rhetoric — little tricks that don’t change the meaning of a sentence, but make it more memorable. The ancient Greeks and the Romans loved identifying and collecting these patterns. They didn’t invent them exactly, they simply observed that some lines are memorable, others are not, and that the memorable lines tend to follow certain formulas.

In Shakespeare’s day rhetoric was still part of the standard school curriculum, so when he used diacope, he knew he was using diacope. These days we tend to thrash about until we get there by accident.

For a figure called chiasmus, a perfect example is “I am stuck on Band-Aids ‘cause Band-Aid’s stuck on me.” If you put it next to J.F.K.'s inaugural speech, you’ll see exactly what I mean. “Mankind must put an end to war, or war will put an end to mankind.” “We must never negotiate out of fear, but we must never fear to negotiate.” “Ask not what your country can do for you... .” You get the picture.

But when I contacted Mike Becker, the man who actually came up with the Band-Aid phrase in the mid-1970s, he told me that he’d never thought of the J.F.K. parallels. “It just had a kind of magic to it,” he told me. And he denied ever having heard of chiasmus.