How many of us miss the Yankee Doodle Coffee Shop even though we never went there?

I have eaten just three meals at the Doodle. Still, its demise saddens me. If only someone had told me it was closing, I might have gone there one last time, or many times, while I still could have.

The Doodle’s vanishing hints at how we may feel at graduation. A trip to the Rockwellian diner is one experience on a list of many that we cannot enjoy anymore — a growing list that someday will include college itself.

The neighborhood is reshaping. Financial struggles plague Naples Pizza, where the tables bear four decades of carved names. New ownership recently swapped the vivid, iconic “Naples” moniker for the uninspired “Wall Street Pizza.” Meanwhile, Mory’s struck a blow last week to its tradition of “toasting” with legendary Mory’s cups. Previously, Mory’s carded only certain members of a party, tacitly letting underclassmen and upperclassmen toast together, even in a raised-drinking-age era. Now, plastic wristbands delineate legal drinkers from the legal at heart. (Hardly consolation: Mory’s now offers non-alcoholic cups. Flavors include “Razz-A-Ma-Tazz.”)

Given alcohol laws, it was a matter of time before Mory’s changed. Still, those who postponed toasting, feeling the tradition would never change, may wince at the fact that it finally has.

In not so long a time, even Gourmet Heaven, A-1 and Clark’s will recede from our world. They may not leave New Haven, but we will.

Only recently did this inexorability register in my mind. One night over winter break, waiting to fall asleep, I realized that my four years of college have dwindled to one and a half years left.

I replayed last autumn in my mind: friends I met up with at Yorkside or ran into in Atticus; the cloth books and leather chairs of Sterling Memorial Library. How did that semester vanish? I could not recall many days in my junior fall semester when I thought, “Here I am, one day closer to leaving college.” Yet there I lay awake, one semester closer to leaving college. In one night, I aged four months.

Then I envisioned places I wished I had gone — Yale’s art gallery, Pepe’s — and people I had not spent time with in too long. On any given day in junior fall, I could trust in tomorrow for those experiences. But I realized that night that the “tomorrows” of junior fall were all used up.

This semester, in a class on Rome, we read the poem that first coined the proverb Carpe Diem. It is an ode by Horace. He wrote: “Even as we speak, envious time flies past. Harvest the day and leave as little as possible for tomorrow.”

I had never seen “carpe diem” translated as “harvest the day.” But I prefer it. The difference between that translation and the traditional rendering — “seize the day” — reveals why, though pop culture trumpets carpe diem to such triteness that it seems facile, it is actually challenging to fulfill.

In college, the impediment to carpe diem is not the stereotypical swamp of quotidian trivialities that so many movies and songs denounce. We do not itch to leave work and our worlds behind. We love what we study and what we imagine and plan for our futures (well, most of the time). Thank God: Finding something to seize is not the problem.

The problem is the opposite. There is so much to seize. In a world full of experiences to revel in and people to know, we cannot harvest it all.

As problems go, this is a lucky one. Still, when something that we had meant to harvest — like time at the Doodle — vanishes, we rue having spent time elsewhere. But more often than not, “elsewhere” was wonderful and ephemeral too: a Master’s Tea, a YSO concert, a friend’s birthday, a paper for a meaningful seminar.

Thrilled gratitude blends with agonized paralysis. In these years, we can do nearly anything — but not everything. Time is running too short for that. We have seen the vanishing of enough tomorrows already: tomorrows to eat at the Doodle; tomorrows left in last semester. We can imagine no more tomorrows left in college.

That scares us. But it can also wake us up.

Not tomorrow, then, but today, we can share excitements and worries with friends who care about us, while we still live close to each other. We can frequent old haunts, while they are still here, and while we are still here. We cannot do all of these things. But we can do the ones that matter most.

We may still graduate wishing we had reveled in these years more. But if we revel in these years to the best of our powers, then we will be sorry we cannot do so anymore and glad that we did when we could. That poignancy is good enough. It is ours to harvest.