Not until college did I realize how radical Thanksgiving is. I always loved it, but now Thanksgiving is a different holiday.

When we were little kids, Thanksgiving generally followed one of two paradigms. The first was the loud kerfuffle of relatives we did not know saying things that we did not understand. The feeling of being out of place and bored silly amid this brash fog of grown-up-ness is a childhood standard.

But a second kind of Thanksgiving was and is possible: a peaceful, genuinely intimate family holiday.

Such a Thanksgiving, though, blends in with the rest of childhood in a way that is unique to those years. When we were younger, Thanksgiving was not extraordinary, but rather, an ideal picture of the ordinary: a day off from school when school was never really that hard; a time at home in an era when we still lived at home; a family dinner when many dinners were family dinners; a time to see hometown friends, when we saw those friends daily.

The purest felicity of all was how little we noticed that these were blessings. We did not know they were impermanent, or that we, too, would change. We thought life came this way. We hardly knew an alternative, for our most major life changes were yet to come (and, in some ways, they still are). So the question of whether our universe was permanent never even crossed our minds. Permanent as opposed to what?

In the ideal childhood — a concept no one lives completely, but which to some extent everyone enjoys — here is simply here, and now is now. Times with friends, family dinners, half an hour of homework, one’s old street, one’s own bedroom with one’s own stuff arranged one’s own way — it makes a marvelous scenery.

College is our first encounter with the idea that “the way things are” can fade into “the way things used to be.”

We are left to face the reality that life could and inexorably will work in alternative ways: that we might actually live on our own; that self-reliance, though its sweet independence is real, can also be exhausting; that we might be surprised by whom we grew closer with, and who we lost touch with; that we might enter a world that too often pressures a person to achieve and rewards him for the credit he accrues for his name.

Now, when we return home to rest, we cannot help but notice that we are home and we are resting. Now, we know what the alternatives feel like. The sheer awareness of rest’s impermanence, with the world’s responsibilities waiting at the door, weighs on a college kid’s shoulders.

Even still, there is good news. This Thanksgiving, I felt that because holidays and reunions are rarer now, they bear the color of a new sweetness, a more urgent one. The feeling springs not from the comfort in what can last forever, but from the poignancy of what cannot.

My parents, my sister and I hardly left the neighborhood this week. We ate soup, turkey, stuffing and rye toast. We took walks down the usual streets. (No matter how long I am away, they are still usual.) We did what I miss the most from pre-college years: we read for pleasure. We caught up on two months’ worth of each other’s stories, the kind of stories that were mundane when we could tell them at dinner any night.

I thought of Samuel Taylor Coleridge’s poem, “Reflections on Having Left a Place of Retirement.” Describing a vacation, Coleridge builds dramatically to the line: “It was a luxury, — to be!” The poem suggests that in a whirling society, to step out of that whirl and simply be is a luxury, for it is rare. To deploy a word that is over-used and under-meant: It is special.

The first time one sees that rareness is a strange moment. If not the single sign that childhood has concluded, it is certainly a strong candidate.

Yet as I edge with disbelief toward my third-to-last semester of college, I wonder if by accepting life’s terms — the difficulty in knowing who I want to be, and how to become that person; the weight of shouldering this responsibility myself; the uncertain shape-shifting of human relationships; and most of all, the impermanence of all times — a new joy emerges.

This Thanksgiving, I decided not to wait for the eternal peace that is not here to start reveling in the temporary peace that is. The fact that a time does not last all that long, and can never be retrieved, is all the more reason to revel.

Here, then, is why Thanksgiving is radical. On Thanksgiving, we do get to step out of life’s whirl. We are civically obliged to. It’s on the calendar.

We can take our eyes off the beckoning future, and what is left to be achieved. We can simply be in the present, with the people we love, and be thankful to be there. That opportunity — Thanksgiving Day itself — is something for which to be thankful.

Noah Lawrence is a junior in Saybrook College. His column runs on alternate Mondays.