If you are going to get a serious disease - and, unless you would prefer to die violently and young, you are probably going to - Parkinson's is not your worst choice. It is progressive and, at the moment, incurable. But, like its victims, it tends to move slowly. It is not generally fatal - meaning that there is enough time for something else to get you first. There is also enough time for a cure to come along, which might well happen if politics doesn't get in the way. And Parkinson's is fashionable these days. It's a hot disease, thanks to celebrity sufferers such as the Pope, Billy Graham, Janet Reno, Mohammed Ali and Michael J Fox. Even, they say, Yasser Arafat.

I might not have chosen to be diagnosed with this old people's malady at the age of 42, although you must admit it's a pretty good joke on someone who used to like being precocious. If life is a race to the finish line, I am years ahead now.

There are three ways to deal with news like this: acceptance, confrontation or denial. Acceptance is an aspiration, not a strategy. Confrontation means putting the disease at the centre of your life: learning as much as you can about it, vigorously exploring alternative therapies, campaigning for more research funding, and so on. Denial means letting the disease affect your life as little as possible. In fact, it means pretending as best you can that you don't even have it.

To me, confrontation and denial seem like equally valid strategies, and the choice between them is one of personal taste. Most people mix and match. But there is no question as to which approach has society's approval. Our culture celebrates aggressive victimhood. The victim - victim of almost anything - who fights back is one of the master narratives of our time, in plays and movies, on television talk shows, in books, in politics, in lawsuits. Meanwhile, few things are more socially disapproved of than inauthenticity or a refusal to face reality. In choosing confrontation, you embrace the community of your fellow victims - another socially approved value. In choosing denial you are guilty of self-hatred, like a Jewish or African American putting on Wasp airs or, worse, trying to "pass" as a white Christian.

I don't mean to ridicule these notions. Even eight years along, I can still pass as healthy most of the time, or could until this week; but there has been a slight pang of disloyalty to the cause in doing so. A woman with multiple sclerosis once said to me, unknowingly, about disease activists in general: "We all pray for someone famous to get our disease." Although I am a very minor public figure compared with the Pope - let alone Michael J Fox - I haven't been doing my bit. Nevertheless, when I got the diagnosis eight years ago, I chose denial. If ever you are entitled to be selfish, I thought (and still think), this is it. So I see a good doctor, take my pills most of the time, and go about my business. I couldn't tell you some of the most basic things about Parkinson's and how it works. Modern culture may favour confrontation but we are genetically hard-wired, or at least I am, with a remarkable capacity for denial. It helps, of course, that the symptoms have been mild. Most days for the past eight years I have hardly given a thought to Parkinson's disease.

In the early stages, Parkinson's is mainly a matter of foreboding, which makes denial an especially effective therapy. If you fool yourself skilfully enough, you can banish thoughts of the disease but retain a liberating sense of urgency. It's like having a get-out-of-jail-free card from the prison of delayed gratification. Skip the Democratic convention to go kayaking in Alaska? Absolutely. Do it now, in case you can't do it later. So what if you had zero desire to kayak in Alaska until faced with the prospect that someday you couldn't? You want to now. And that's good. Although I wouldn't actually recommend Parkinson's for this reason, the diagnosis is a pretty valuable warning shot from the grim reaper. The victims of September 11 had minutes to list their regrets. I've got decades to scratch items off the list.

So I recommend denial - and defend it as a legitimate option. To work effectively, though, denial requires secrecy, and secrecy pretty much requires deception. It is simply easier to go through the day not thinking about Parkinson's disease if the people you interact with don't know you have it. This complicates the case for denial. Deceiving yourself may offend the cultural prejudice in favour of relentless self-knowledge, but it does not offend me. What you do with yourself in the privacy of your own head is nobody else's business. On the other hand, deceiving those around you is more troublesome. Especially if you are a journalist, whose whole professional value system is wrapped up in the idea of the truth: demanding it of others, telling it yourself.

For eight years I have tried not to tell outright lies, but there have been some Clintonian evasions and prissy parsing. (Q: You look tired. Are you OK? A: I feel fine.) And my basic intention has been to deceive. So I'm sorry about that. Some topics - is it decaf? - require absolute honesty. With others - military secrets, non-contagious diseases - there may be legitimate exceptions. The least a misfortune can do to make up for itself is to be interesting. Parkinson's disease has fulfilled that obligation, among other ways, by plunging me into a maze of deception and self-deception. I have no idea how well my efforts at deception have worked, and I don't intend to believe everyone who claims now to have known all along. But in the past couple of years, it seems to me, the symptoms have become more evident. There have been rumours. And the short, somewhat random, list of people who know my secret because I told them has grown longer - probably too long for all the pledges of secrecy to hold.

I have come to assume that many or even most of the people I interact with every day actually do know my secret and are pretending not to. It has been like living in that classic childhood fantasy (which was the basis of the Jim Carrey movie, the Truman Show) that what seems like reality is actually a giant play everyone else is performing for your benefit. Only this play has a Pirandellian twist: while they are putting on a performance for you, you are putting on a performance for them. Or are they? (And are you?) Even this orgy of mutual pretence was better than facing the truth in every dealing with other people, I thought and still think.

But, eventually, plugging holes in the dyke comes to seem more trouble than it is worth. So now I am out. The next phase will be interesting as well. Call it part two in a controlled experiment, testing those fancy French theories about disease as a social construct. I was officially, publicly healthy. Now, with almost no objective medical change, I am officially, publicly sick. How will that change the actual effect of the disease? Without, I hope, distorting the experiment, I predict that this notion of disease as a function of attitudes about disease will turn out to be more valid than I would have suspected eight years ago.

Those around me who knew will now be able to stop acting, but my own acting burden will probably increase. Everyone I deal with will be scrutinising me for symptoms - loving friends and relatives most of all - just as I myself scrutinise friends and relatives who are chronically ill. Up to now my audience has been either non-suspecting or constrained to pretend that it didn't suspect.

From now on they will all know the script I am trying not to follow. My performance, to be convincing, will have to be better than normal. If you are normal, or people think you are, you can clear your throat or trip on a rug or complain of a headache without raising eyebrows. When people know it is partly performance, you can't.

Anyone who develops a chronic disease in mid-career dreads being written off - being thought of prematurely in the past tense. Three years ago I was offered the editorship of the New Yorker. I told the owner I had Parkinson's and invited him to change his mind, but he generously said it didn't matter. A few hours later, though, he withdrew the offer with no explanation. I chose to believe him that the Parkinson's didn't matter. To withdraw the offer for that reason would be, among other things, probably illegal. But I also doubt that he would have made the offer in the first place had he known all along.

Parkinson's is the disease most likely to be cured by stem-cell research, which is enmeshed in controversy. As I wrote in Time magazine a few months ago, you can't really criticise people whose reason for opposing research that uses embryos is that they truly believe embryos are fully human beings. But you can criticise politicians who try to escape this yes-or-no dilemma with calls for compromise or delay or prestigious panels to study the situation and report back in a few months. Can't they hear that sound of clocks ticking? Tempus fugit, assholes.

As we have all discovered since September 11, the news is a lot more interesting when your life may depend on it. So that is another little plus of having Parkinson's disease. I don't delude myself that the pluses add up to equal the minuses. Though I may give that a try.

· This article first appeared in Time Magazine. Michael Kinsley is the editor of Slate.com