I've never had trouble falling asleep. I have dozed off on trains and snoozed until I missed not only my stop but my entire state. I have slumbered standing under a steaming shower and been shocked awake, looking like a candidate for a full-body Botox, when the water turned cold.

My dentist has had to shake me awake to continue drilling my teeth. It's an odd thing, being on the verge of unconsciousness all the time.

The government has a word for people like me: dangerous. We cause roughly 100,000 traffic accidents every year, according to the National Highway Traffic Safety Administration. In the process, we injure about 71,000 men, women and children, including ourselves, and send 1,550 people to early graves.

So when my own misadventures in wakefulness started to include unfriendly car horns waking me at traffic lights, I figured I'd better get professional help.

Dr. Marc Kawalick, medical director of the Sleep Disorders Center at New Britain General Hospital in Connecticut, had a ready smile and a vise for a handshake. His staff had told me to keep a sleep diary for a couple of weeks — a record of when I slept at night and when I felt tired by day. The doctor carefully reviewed it.

"There does seem to be a pattern," he said, "but we'll see."

I took a test and was proud of scoring 23 out of 25 possible points on the Epworth Sleepiness Scale (search) — until I learned it was like golf: Low score wins.

"And you snore, you said?"

"It wakes even me sometimes."

One night a few weeks later, I donned pajamas in one of the center's hospital bedrooms. An attendant pasted 22 electrodes all over my head, face, chin, chest, stomach and legs. Tests Kawalick ordered included a Multiple Sleep Latency Test, a monitoring of my wakefulness at two-hour intervals for the rest of the day.

It took three weeks for my results to be evaluated, more than enough time for me to ponder my lifelong problem — four decades' worth, going all the way back to high school in Keene, N.H., in the early 1960s.

Before my father died, he made me a rock maple desk so I'd have a place of my own to do schoolwork; and this I attempted, five nights a week, while listening to Top 40 rock on my Magnavox radio. I usually picked up the countdown in the low 30s; but by the time it reached the single digits, my head slumped onto the desk, drooling.

The truth that emerges through those years is this: Although I was reasonably bright, I never was going to excel at anything requiring prolonged concentration.

I fell asleep so regularly that teachers, family, most of the adults in my life, formed a chorus: "How can you be tired at your age? Know how you spell that? L-A-Z-Y."

I figured that everyone got as tired as I did and just handled it better. I was different, maybe inferior — too darned listless to have much hope of making my way in the world.

I wonder now what I might have learned had I been as awake as everyone else.

I wonder, too, if the depression and anger that complicated and soured relationships for most of my life were problems unto themselves or rooted in my indescribable weariness.

I do know this: After weighing years of what had been, against intimations of what might have been, I feel sad and oddly removed from major parts of my own life.

My high school grades were good enough to get me into the state university. But my lecture notes consisted of a few legible paragraphs followed by indecipherable scrawls that drifted off the page.

Joining 200 other students for a geology midterm, I awoke an hour later with no one left in the amphitheater but me and the scowling teacher.

My grades were not swell. After two semesters, I slinked home in shame and went to work in a furniture factory. Through a haze of spray lacquer and sawdust, I got a quick glimpse of the rest of my life. So I saved as much as I could, and after a year returned to the university, chastened and determined.

This time I had a strategy: Take afternoon and evening classes, study subjects I loved, and study obsessively in odd hours of wakefulness. But I could not will myself to stay awake, even in my favorite cinema classes. When the lights went out, so did I.

On a date, I could be a laugh riot, and I'll leave it at that.

Then came the night that I drove a Ford Falcon wagon straight off a New Hampshire highway, my foot a dead weight on the accelerator. I roared down an embankment, tore down 350 feet of barbed-wire fence and ripped out the undercarriage on fieldstones.

I awoke to see the limb of an apple tree fill my headlights and made it to the floor just as the windshield blew straight into the back seat.

Somehow I stayed alive long enough, and learned enough, to attend the best journalism graduate school in the country and get a job at a fine daily newspaper.

News is all the time, so I could sleep for 14 hours and then do a full day's work, or sleep for four hours and grab a nap at my desk. As long as I got the story, no one cared. For the first time in my life, my inclination to function without regard for the clock was not a handicap.

Occasionally, though, there were glitches.

One evening, I was assigned to watch a televised address by President Carter with a Brown University political scientist. We took comfortable seats in the newspaper's editorial library.

The president spoke for about 20 minutes; I slept for 17. The professor was gracious. He woke me to say what he thought of the speech and I wrote the story.

Given the persistence of such episodes over the years, the results of the tests administered by Dr. Kawalick should not have been a surprise.

"You have narcolepsy," he said.

"Are you sure?"

The overnight test had proved, as medical folks are inclined to say, "unremarkable." The daytime test was anything but.

I had not merely fallen asleep in the middle of the day — more than once. I had skipped the first stage and plummeted straight into REM (Rapid Eye Movement) (search) sleep, the realm in which we dream. Most people take from 16 to 90 minutes to get there. Slackers! I needed an average of only 1.4 minutes.

Narcolepsy (search). I already knew a bit about it — that it is neither fatal (except when combined with heavy machinery) nor curable, but that it carries with it an annoyingly understandable lack of sympathy.

"Well, what now?" I asked the doctor.

Scientists had recently discovered that narcolepsy appears to be caused by the lack of a chemical neurotransmitter in the hypothalamus (search) at the base of the brain. The scientists' best guess is that it is destroyed by an attack on the immune system. The discovery has been hailed as the most significant step in the understanding of narcolepsy since 1877, when the disorder was first described in Germany. The hope is that by manipulating levels of chemicals, science some day may be able to cure narcolepsy.

For now, Kawalick said, all one could do is try to control it. He prescribed modafinil.

He also advised me to take a multivitamin and be ruthless about getting eight hours of sleep every night.

I followed the instructions, and the difference was remarkable. I no longer felt tired all the time. But with this new vitality came an acute awareness of just how much of a problem my narcolepsy had been, and for how long. I felt like a dunce for not having known.

And yet, sleep disorders are grossly under-diagnosed, and usually diagnosed late — an average of 15 years late, according to the National Sleep Foundation.

"Sleep complaints usually have just been treated as nuisances" by both patients and doctors, Kawalick said, but attitudes are changing.

In 1988, the year the hospital's Sleep Disorders Center opened, Kawalick and his staff conducted about 100 tests. This year, the center expects to conduct more than 1,600. And drugs such as modafinil have given doctors the ability to treat narcolepsy more effectively.

Gradually, my daily dose had to be increased to offset other medication for less interesting maladies. In time, it was costing about $20 a day to keep me awake.

After nearly four years of taking the drug faithfully, I was certain I had my narcolepsy in hand.

That was an illusion.

On Feb. 21, 2003, I was alone in my Toyota in high-speed, 5 p.m. traffic on the outskirts of Providence, R.I. I don't remember getting drowsy. I do remember bolting upright when I hit the rear bumper of a pickup truck and began pushing it off the road. There were no injuries, nearly a miracle by anyone's standards.

"And you had no warning?" Kawalick asked. "No nodding-off just before the accident?

"No," I said. "Not that I can recall."

"Anything in the past few weeks?"

I paused long enough to suggest stupidity. A week before the accident, same time of day, I had nodded off at a stop light. I'd been doing so well that I had shrugged it off as a fluke.

"All right," Kawalick said, "I'm telling you officially that you cannot drive safely right now."

In nearly every state, such a warning takes you off the road until the doctor tells you otherwise. California is even tougher, banning diagnosed narcoleptics from driving.

Kawalick tested me again, and I failed again. He increased my dosage of modafinil, added Ritalin, and told me I now needed nine hours of sleep nightly along with my daily nap.

It worked. Seven weeks after the accident, I was able to pass the wakefulness test and resume driving.

Still, I am wary. I trust myself to drive only short distances, and only if I've napped. No exceptions.

I told Kawalick I never would have driven a car if I'd had any reason to think I was a menace. And then I told myself the same thing.

But my intentions were beside the point.

My wakefulness may never have been total. It may not be now. It may never be. I am left with a functional, compromised awareness swirling across a thin and treacherous surface.

Beneath it, at the core of me, is narcolepsy — just a fancy name for exhaustion. Utter, complete and irresistible.

Wayne Worcester is a professor of journalism at the University of Connecticut.