I was in the operating room the other day, taking a fellow through a complex case—Fellowship comes after residency and after medical school and is the final stretch of a surgeon’s formal training, the season where skill sharpens into judgment and repetition becomes true understanding. At every teaching moment, I found myself attaching the lesson to a patient I once treated, a mistake I learned from, a complication that humbled me, or a small victory that shaped the surgeon I became. Each pearl of wisdom had a name, a face, a story behind it. None of it came out of a book.

And as I guided him—steadying his hand, offering the nuance that never makes it into lectures—my mind drifted for a moment to my daughter at home, filling out college applications at the kitchen table. She’s in her own threshold season—counting the days until graduation, watching the clock the way all teenagers do, convinced that life begins just after the next deadline.

Between them, I could see the entire arc of how we relate to time:

She wants time to speed up.
He wants time to slow down.
And I am learning to honor the time that remains.

The truth of it hit me with surprising force:
we spend our early years waiting for time to move,
and our later years wishing we had paid closer attention while it did.

Surgeons rarely teach from abstraction. But the truth is broader than surgery. In every field—law, teaching, engineering, carpentry, parenting—people pass on what they know through lived experience, not theory. Wisdom accumulates privately, unevenly, often painfully. Textbooks offer the outline; life provides the meaning. And the longer someone practices their craft, the more their knowledge becomes a lineage—carried through stories, gestures, instincts, and the quiet authority of having been there.

So when I glanced past the wall clock and realized it was already dark, it startled me. I hadn’t looked at the time once. And the question that rose wasn’t, “Where had the day gone?” but the deeper one that arrives in the later stages of a career:

Where have the days gone?

When I was a teenager working odd jobs, time was something I stared at. I watched the second hand drag itself forward as though it had no destination. I counted minutes because I had nothing else to count. Adolescence is built that way—too little purpose, too much waiting. You want time to speed up so life can “finally start,” never realizing the slowness is its own kind of inheritance.

But somewhere along the way, the clock disappeared.
And when it returned, it came back with a different face.

In medicine, the hours slide past unnoticed while your attention is fixed on a suture, a sick patient, or a decision that cannot be undone. But this isn’t unique to medicine. Anyone fully absorbed in their work—teachers, pilots, builders, founders, first responders—knows the strange quickening of time when the task matters more than the clock.

And yet, this immersion carries a cost.

Time subtracts quietly at first—missed dinners, meaningful conversations shortened because you were “too busy,” a season of your children’s lives you only now realize you half-witnessed.
Then the subtractions grow heavier.

Your children become adults.
Your parents slow down.
A mentor-the person who once stood at your shoulder the way you stand at your fellow’s-dies.

And suddenly, you understand the geometry of time in a way you never did before.

At a certain point, without realizing the moment it happened, you look around your team and see that you have crossed an invisible threshold. You are no longer the new one. No longer the young one. You are the one who has lived the most experiences, absorbed the hardest lessons, and carried the deepest responsibility to pass them on.

It is not just surgeons who cross this threshold.
Every professional life has a moment when the arc flips— when you go from being shaped to shaping others.

And in that moment, time stops being something you ignore
and becomes something you deeply understand.

Not with regret—never that.
But with purpose.

Because time has been teaching all along:

Childhood teaches impatience.
Training teaches absorption.
Only a later season of life teaches intentionality.

You begin to see the long arc of your work. The projects, cases, students, patients, or clients blend into something larger than any single day. You remember not the most complex tasks, but the ones that reminded you why the work matters. You look at your colleagues, your parents, your children—and you see time moving through them too.

And suddenly, the questions change:

What am I building that will last?
What knowledge am I passing on?
What wisdom am I offering?
What part of me continues when I am no longer here to guide it?
What story am I still writing—and who is it for?

People in this stage of life across every profession feel a quiet tension—not fear of time running out, but the pull to use the time that remains well. Because by now you understand something you didn’t before:
time is not a clock.
Time is not a schedule.
Time is not the enemy you once imagined.

Time is a stage on which you choose your next act.

And the paradox is simple:
When we are young, we beg time to move faster, unable to imagine a life where the hours disappear into meaningful work.
Later, we find ourselves wishing those same hours would return, forgetting that we once pleaded for them to pass.

At this point in life, the questions fall away.
What remains is a recognition: time is not fixed.
It shifts with us.
It reflects who we are in each season.

To the young, it is a barrier.
To the striving, it is a resource.
To the seasoned, it is a gift—
one that continues to be unwrapped.

And as you look again at the fellow beside you—absorbing everything as fast as he can—
and at your daughter racing toward adulthood—impatient for life to begin—
you recognize the quiet truth:

They are each unwrapping the gift of time in their own season.
And you are finally learning what to do with yours.

Because the work ahead—the meaningful work—
is no longer defined alone by how much you can produce,
but by what you choose to do with your remaining days.

It is the work of intention.

The work of meaning.

The work that remains when all the rest is done.

And that, I’ve come to realize, is the true gift of the hours.

By Michael M. Karch, MD, FAAOS. Mammoth Orthopedic Institute | Harvard Business Analytics Program | MIT Executive Program in Machine Learning