I was an unhappy 18-year-old camp counselor enduring a very long summer, and I thought that if I could only be elsewhere, I’d be happy. On a calendar in my room, I marked each passing day with a black X. My grandmother, who visited one weekend, saw the calendar and said, “Doll, you shouldn’t do this. You’re wishing your life away.”

Thirty years later, as the mother of six, I still often find myself impatiently anticipating the next activity, engaged in one thing while planning another or rehashing the last. I no longer draw X’s on a calendar, but I tick off hours and days all the same.

At the grocery store, I think about getting to the soccer field. Making dinner Tuesday night, I fret over the kids’ Wednesday lunches. When I’m with one of them, I worry that I’m slighting another. I’m never where I seem to be. My iPhone has made it worse. No matter where I am, I can be somewhere else. Even when I’m talking on the cell phone, I can read text messages. Bored with a book, I check my e-mail.

What’s truly important, of course, rarely arrives by e-mail. It comes in the moments of an ordinary day: the way my youngest feels at night when he climbs into my bed, the scent of my teenage daughter’s hair when I hug her, the feel of my husband’s cheek as he kisses me goodbye. It comes in the message from a friend who just wants to talk or the face of a child who needs my attention.

But these moments often occur when my mind is fluttering elsewhere, as fast and unfocused as a hummingbird on a geranium.

Then I started taking boxing classes. And I discovered I couldn’t be anywhere else at the same time.

If I’m throwing a hook, it’s all I can do to keep my hips and legs in it, to maintain balance and focus. On the ground doing iron-cross hurdles, I can think only about whether my legs are moving high enough off the floor. For the two hours a week I spend in class, I have no choice but to be in the moment.

It hit home for me the day the trainer had us do a minute-long “wall sit” while holding five-pound weights parallel to the floor: Back low against the wall, I sat as if I were in a low-slung beach chair. A few seconds into it, he told us to focus on what we were doing, not try to pretend we were somewhere else—such inattention can leave a boxer vulnerable. He said to focus all of our energy on staying put, remaining seated against the wall, not giving in to fatigue.

To get through it, I began whispering, “I am here, I am here, I am here.” For that moment, I was—engrossed in the sensation of pushing my body to its limits.

I’ve been practicing saying “I am here” in other situations, trying to remind myself I have only the present in which to live. It’s taken me almost 50 years to learn this, to plant my feet where I am, to feel “I am here” as I clatter away at the keyboard, feel the laptop’s battery warming under my palms, the light glowing before my eyes.

I am here, the only place I should be.