You've heard of (and been ragged on) about run-on sentences, so imagine what your English teacher would say about Octavio Paz's 584-line never-ending sentence? Probably nothing good. But once they read the first line, they'd be hooked.

That's because "Piedra de sol" is Nobel Prize-winning author Paz's masterpiece poem, and that's an understatement. Paz is kind of a big deal in Mexican culture—he's got the kind of name you'd do well to throw around at fancy tequila cocktail parties—and that fame comes from being Mexico's only Nobel laureate for literature. He tackles big issues like what it means to be Mexican in moving poems and stories.

"Piedra de sol" is one of those poems. It takes us through the long process of trying to recall one of those tricky memories of a long-ago love, and it does so in one endless loop, as its last six lines are exactly the same as the first six. The poetic voice goes through a cycle of forgetting and hating that he's old and forgetful, finally landing at death and the ultimate communion with the universe and all time. Cosmic, right?

Besides the obvious coolness of a circular sentence—who wouldn't want to trick their readers into eternally reading their poem?—the title gives us the clue to Paz's inspiration for the poem. The sunstone, or piedra de sol, of the title refers to the round Aztec calendar, which had 584 days per year. Remind you of anything, like, say, the number of lines in the poem? (Note: In original Spanish, the poem has this many lines, but alas, the English translation did not preserve this number. So it goes.)

The Aztecs were in charge of Mexico City when the Spanish arrived, and had a pretty advanced civilization with really accurate astronomic systems, which they depicted on sunstones like old-school calendars. The 584 days measure the movement of the planet Venus, which means the poem reflects on memory, time, and even eroticism. Sure, Paz's writing was always concerned with Mexico, but he was never one to shy away from big universal themes. And what better place to start poetic ruminations on memory and time than the awesomely intricate Aztec calendar?

The speaker in "Piedra de sol" is an old guy obsessed with a memory of a girl from a long time ago that he's somehow forgotten. So what does that have to do with young students who are more interested in making memories than trying to recover them?

A lot.

The memory the speaker is trying to recall happened in the prime of his life—he had lots of girlfriends, he traveled to foreign lands, he even witnessed a war. And now those things that were the most important things in life are lost. He can't get back to them, and is really ticked off about the fact that death grows ever nearer.

So now it's your turn. Imagine the parts of your life that seem so real, so unforgettable—your first kiss, your favorite summer vacation, graduation—all being wiped clean from your memory. You might go on a mad quest to figure out what happened, Memento-style, and get into all sorts of trouble. Or you might ignore the problem and go about your life, only to be considered the fool of the sea, like Dory in Finding Nemo.

Either way, you're missing something. Life is meaningful because, well, we can remember it. Without those memories, the things that make you you are gone. And that means that the loss of memory that comes with growing old and dying is a painful, scary experience. So give the speaker a break—put yourself in his shoes and you'll see why his need to remember is so urgent.