It’s all there in the Satipatthana (“Foundations of Mindfulness”) Sutta: The direct path to awakening calls for maintaining awareness of body, feeling, mind, and thoughts—and not just when we’re sitting in meditation. Whether eating, drinking, chewing, urinating, defecating, walking, standing, falling asleep, waking up, talking, or remaining silent, we must remain fully alert, the Buddha said.

There’s a high cost to not paying attention, as one of the Buddha’s parables on mindfulness suggests. Imagine a large group of people gathered around a famous beauty queen, watching her sing and dance. A man comes along, and he’s handed a bowl filled to the brim with oil and told he must carry the bowl on his head between the crowd and the beauty queen without spilling a drop, or a guy following along behind with a sword will cut off his head. “What do you think, monks?” the Buddha asked. “Will that man allow himself to be distracted from the bowl of oil?” Naturally, the monks said no.

Life is just one situation after another in which we have to choose between staying mindful or losing our heads. I often think of daily life as Thich Nhat Hanh’s mindfulness bell, endlessly reverberating with people and circumstances that chime Wake up!

When it comes to mindfulness on the hoof, even the movies can be a form of training. A good movie is like a Zen teisho, or teaching talk: it can open you up to a deeper awareness. Something like that happened to me watching Letters from Iwo Jima. For the first hour or so of the movie we eavesdrop on a handful of Japanese soldiers and their general as they wait for the invading American forces to strike. Excerpts from their letters to loved ones and flashbacks of their lives back home give us a sense of these men, but it’s their conversations—intimate, banal—that are almost unbearably poignant: they know, as we do, they’re about to die. The attack is a given, yet when the screen suddenly explodes in a hail of bombs and mortar fire, blood and screams, I recoiled as if I, too, were under siege. I ducked and squeezed my eyes shut. As the battle raged, it was mirrored in my inner turmoil—thoughts and feelings shooting off like rockets, about human brutality, the evils of war, the warmongers in power. Caught between sorrow and rage, I burst into tears. Sneaking a look at the people around me, I wondered: How could they sit there so calmly? Why wasn’t everyone upset? Or was I overreacting?

Desperate to stop the war in my head, I focused on the breath rising and falling in my chest. Soon, a space of calm opened up inside me—the sort of peace the novelist Orhan Pamuk described as “the silence of snow.” On screen, the mortar fire continued, but I experienced it at a distance, no longer overwhelmed. For the first time, I could hear the noise for what it was—a movie soundtrack. The thought of the carnage was still horrifying. But when I separated the sound from the story, the ka-booms and rat-tat-tats were only a series of vibrations emanating from a bank of speakers and ricocheting off the theater walls.

To know the truth of what is there—not the echoes and shadows on the walls—is the beginning and end of mindfulness. Once I was able to disengage somewhat and observe the kaleidoscope of sensations and thoughts, the feeling of aversion began to subside. I could open my eyes and watch the rest of the movie without collapsing into self-centered distress. The images on the screen were no less brutal, no less wrenching than before, but without the running monologue in my head—This is terrible. I’m so miserable. Why do we kill? I hate violence—genuine empathy could emerge, and compassion for whatever in us needs to fight.

Mindfulness is not easy—it calls for diligence I can’t always muster. One problem is, I’m so much more conversant with its opposite—mindlessness. Not the Zen teaching of No Mind but everyday obtuseness—the Adam-and-Eve-in-the-garden kind of heedlessness that carries on without any thought to the consequences. Mindlessness can be extravagantly self-indulgent: I agonize over things I can’t control—the war in Iraq, the health care crisis, rampant incompetence and incivility, tax breaks for billionaires—while what I can control cries out for attention. More often, mindlessness takes a simple, albeit perverse, form: misspending the afternoon with a stack of magazines and a cup of tea when an important deadline looms.

Like all mindless activities, this comes to no good. The magazines, once read, are discarded. The tea is consumed. Yet the deadline looms even larger, a hurricane gathering force. Mindlessness, however petty, is reckless at its heart. It only postpones; it never takes us anywhere. Mindfulness, by contrast, is patient, careful. It takes a longer view.

Want to see the difference between mindlessness and mindfulness? Meet me in midtown Manhattan around noon. I’m running late for an appointment and elbowing my way through the crowd. People are lurching this way and that, too engrossed in their cell phones to fall into the unspoken dance that keeps traffic flowing along without mishap. Crash. Someone sideswipes me without pausing or murmuring “I’m sorry.” Oof. Someone else steps on the back of my shoe and, when I lean down to adjust it, shoots me a dirty look. By the time I reach the corner, I’ve had a half-dozen or so of these encounters and dodged a dozen more. And I still have blocks to go.

Mindless-Me plows on, muttering at people who don’t walk fast enough, snarling at those who cut me off. By the time I arrive at my destination, I’m in a foul humor, barely able to paste on a smile or proffer a polite greeting. Twenty minutes go by before my breathing and blood pressure return to normal and I can turn my attention to the business at hand.

How different this same scenario looks when approached mindfully. I take time to center myself in the breath before I step into the crowd. My thoughts are neutral, not armed for blood. I walk at a relaxed but steady pace, attentive to where my feet are and where they’re headed. I have nary a collision with the cell phone–toting hordes. At the corner, I wait patiently, not jockeying for position so I can bolt across when the light changes. I arrive at my destination on time and calm, ready for whatever lies ahead.

Thich Nhat Hanh speaks often of the “miracle of mindfulness.” It’s a miracle for me to walk a block without working myself into a lather or, at the other extreme, losing myself in worries about tomorrow or a rehash of last night’s conversation. Simply bringing my attention to the moment can change the timbre of my day.

There was a time when I couldn’t live a minute in the present. I knew nothing of bare attention, or nonjudging awareness, or the truth of impermanence. When I felt miserable, I had no faith the discomfort would ever pass. One night when I was still new to meditation, I lay awake for hours in agony from a badly sprained ankle. Finally I decided to see what would happen if I meditated with the pain as my object. The result astounded me.

I recalled a teacher’s suggestion: “Get curious about your experience.” I had never before stayed with pain long enough to be curious about it, much less to investigate it. Whenever my knees or back hurt during meditation, I escaped into counting breaths or repeating my koan. I might notice when the pain stopped, but I noticed nothing of its nature. Was it burning, stabbing, throbbing, dull? Was it steady or intermittent? Were my muscles clenched or relaxed? What thoughts did the pain trigger?

Lying in the dark that night, I greeted the pain as a sensation I’d never met before, and explored each flutter and twinge. In time, the pain eased, and I drifted off to sleep.

If physical pain can change under scrutiny, would the same thing happen with emotions? I wondered. My aversion to physical suffering was nothing compared with my fear of facing emotional distress, despite years of therapy. But here, too, mindfulness served. Under observation, the mental chitchat seemed less diverting. And when painful feelings arose, the practice became how to note them without retreating, how to investigate them without obsessing. Troubled relationships and long-simmering resentments began to unravel.

Not that I can claim a perfect mindfulness score. On the cushion I struggle, spending more time, it seems, shooing my attention back to the object of meditation than attending to it in the first place. Off the cushion, I still lose my cool more often than I’d like, leaving the door ajar for more problems to waltz in.

Even a semi-awakened mind, however, has a harder time kidding itself. I can tell immediately that I’m off when I fudge the truth, don’t pay bills on time, or poison the world with my ratty mood. When I slip up, I know enough to learn the lesson or make amends. There’s a saying in Alcoholics Anonymous: AA ruins your drinking. In like fashion, mindfulness ruins a thousand nasty habits, from “justifiable” anger and schadenfreude to laziness and overspending. Mindless behavior has less kick when you’ve been practicing for a while.

The Buddha’s teachings on mindfulness point to one end—realization and release from suffering. Still, there are rewards along the way—greater compassion and a clear conscience, for two. And even, dare I say it, happiness. We all want to be happy, but as the monk Matthieu Ricard has pointed out, “there’s a big difference between aspiration and achievement.” The quick fixes and immediate gratification I think will make me happy never do in the long run, leaving me empty-hearted. Mindfulness digs the truth out from under the excuses and confusion, lighting the way to true satisfaction. Now if I would just pay attention . . .