I am thankful for many things, principal among them contact lenses, the Internet, and no longer being a child. Surely, we can all think of things to be thankful for; in fact, many of the things we ought to be very thankful for (The Nazis were defeated! Womenfolk can vote!) are exactly the things we are fortunate to be able to take for granted.

But sometimes gratitude becomes more of a positive thinking exercise. When things aren’t great, we hack gratitude. I wrote in last week’s column that having a vertigo-inducing illness helped me develop empathy and time-management skills. Nothing wrong with finding the proverbial silver lining.

Eight years ago, though, I ran a failing dot-com (and, really, a failing life). I read a lot of Tony Robbins books, which kept me thinking so very positively that I thought I could fix a company that couldn’t be fixed. I stayed stuck. I was so depressed, so mired in failure, that I all I could do was read positive-thinking literature … and then go back to bed. (Meanwhile, I was endorsing the books to anyone who would listen. “They really work!” They sort of work at changing a mythical, non-real world inside your head. Amazingly, that world just stays inside your head! It is not real, for the exact same reason that other people are real and often have goals that are opposed to your own!)

Here is a Punnett square that, I think, sums of the usefulness of gratitude as an emotion:

(Seriously, what kind of career columnist cockblocks Thanksgiving? Oh, this one. Just a little. It is called “Bullish,” not “Eat Bland, Fattening Food and Be Lazyish.”)

In sum, gratitude where gratitude is due. Some people, in times of melancholy, even find it helpful to make a list of things for which they are grateful. Cool. And if you’ve lost your legs in a run-in with the J train, be grateful that you are alive! If you can force yourself to be grateful that being a double amputee has allowed you to meet so many amazing people in the amputee community, etc., by all means, try to feel grateful, but if you don’t, feel free to just sue whoever’s responsible and fill your days with Scotch and righteous anger.

Barbara Ehrenreich wrote powerfully in Bright-Sided: How Positive Thinking Has Undermined America about being made to feel guilty that she wasn’t “staying positive” about her breast cancer, and how even cancer patients with terminal diagnoses were bullied into calling themselves “survivors.”

Ehrenreich rails extensively against an impenetrably blithe approach to life. Irrational optimism leads to ill-preparedness. Assume it won’t rain, and you’re the one caught without an umbrella. Assume that a credit bubble will continue indefinitely, and you’ve got a subprime mortgage debacle on your hands.

A friend of mine is 28 and recently married. She wants children eventually but isn’t seriously thinking about it yet. I wrote in the column Financial Planning for Motherhood (Just In Case You’re Not Swedish) about just how soon fertility tanks. All bets are off after thirty-five — for every happy thirty-eight year old mom you know, there’s probably someone else on your list of acquaintances who is devastated by infertility, but less vocal about it (people who are happily pregnant tell everyone; people who are suffering from infertility generally stay quieter, thus creating a reporting bias and furthering the misconception that all those forty-year-old celebrities really just got knocked up with their very own eggs).

So, my friend makes some cute comment on Facebook, along the lines of “I watched my friends’ kids and they were sooo loud that maybe I’ll wait on having my own.” A bunch of her friends, whom I do not know, take the comment a bit seriously and start remarking that 36, 37, or 38 are great ages at which to start having children. I post some kind of dry statistic (here’s a good link) — I don’t want to get into a debate with strangers about this. And my friend’s friends post a series of responses that go like this: “Oh, don’t worry about it! I never thought for a minute that I wouldn’t get pregnant at 37, and sure enough, I didn’t have any problems! Be optimistic!”

If I may refer back to the Punnett square above (knowing, of course, that gratitude and optimism are not the same thing): If you are already 37 and want children, and hence in a bit of an undesirable position that you can’t control, then by all means, proceed with optimism and an indomitable spirit (possibly soon to be imbued with artificial hormones!) But if you are twenty-eight and with the intended father of your future children, “optimism” is simply an inappropriate response to something well within your control. If you want kids before it’s too late, take steps (like making a plan with your partner). If you want to get rich, take steps (like getting started with investing, or starting a business). Optimism in these cases is cute, but wholly insufficient to the work ahead.

Once, in the 1990s, I was declared debate champion of a mid-sized Southern state (also cute, right?) One of the things you do when preparing to compete in a debate tournament is that you imagine that you’re debating against any manner of other debaters, and imagine what they might say, and then you map out your counterarguments. You want to imagine the most astute possible opponents to make sure you are prepared for a brilliant deployment of, say, the second formulation of Kant’s Categorical Imperative. Mapping out responses to the most potent of antagonists is a way to lessen their power.

Starting a business — or planning a life — will go much better if you think in this way. If nothing goes wrong, how will you ramp up your current career? Will you also write a book, start a side business, have kids, engage in philanthropy? If you lost your job, what would you do in the first week? Reach out to contacts to look for a new job? Start your own company? Can you take steps now– such as putting money in the bank, or asking those contacts out to lunch and maintaining those relationships — to make those steps easier then? If you were partially disabled, how would you change your career? Before you have kids, can you make a plan for what you would do if, afterwards, you could only work 80% as much? Half as much? What if your child had special needs and your working capacity were greatly reduced? What if your parents got sick? Can you make a living while living on planes? Is there something you do now in person that could be turned into a book, manual, video course, etc. that you could sell if you couldn’t perform that function in person? Get a giant sheet of paper and make a map of all the things that could go wrong, and how you would respond. Then feel optimistic if you like. There’s some reasonable evidence for the idea of self-fulfilling prophesy; if you think that the best option on the map will happen to you, perhaps, in a thousand small ways you’re not even thinking of, you will help it to happen. Sure. But you can’t put all your eggs in that basket. Be an optimist who also carries an umbrella.

When the great Christopher Hitchens was diagnosed with esophageal cancer in June, his response was a rational one. Not “Why me?” but “Why not me?” In response to those who suggested that his cancer was God’s punishment for atheism, he wrote, “The vengeful deity has a sadly depleted arsenal if all he can think of is exactly the cancer that my age and former ‘lifestyle’ would suggest that I got.”

And then he got right back to writing, arguing against irrationality, and even throwing his weight against “the lethal idiocy of the godly opponents of stem-cell research.”

While my trials have been far more quotidian, nothing better ever happened to me than the failure of my company in 2003. I was working so hard at thinking positively — constantly feeding energy to my internal spin doctor — that I was too sapped of any actual volition, and too self-brainwashed to simply give up on a bad idea. I crashed and burned. I moved to New York. I prepared for the worst. Some of it happened. Some better things also happened. I did more of the things that led to better results.

Positive thoughts are a great thing to send out to actual humans who deserve them. Positive thinking, if you can manage it, is one way (but not the only way) to cope with negative things you cannot change. But positive thinking is a crippling, Huxley-esque hallucinogen when applied to those things we can change, but instead choose merely to think differently about.

Not to overuse the c-verb, but it is realism — rather than optimism — lets you cockblock ill fortune.