Wrong again. When researchers factor out all the circumstantial vagaries of life — everything from income and employment to marriage and education — time’s independent effect on life satisfaction turns out to be U-shaped, with the nadir (in the U.S.) at roughly age 50.

In other words, time fights life satisfaction through midlife, but then it then turns around, helping us feel grateful and fulfilled right through old age. At the bottom of the curve, we often experience a multi-year funk.

When high-performing people hit the bottom of the U-shaped curve

The happiness curve is not unique to professionals. In fact, it is not even unique to humans; a version of it has been observed in chimps and orangutans. But successful professionals seem to be more likely to feel it.

Why?

High achievers are wired to be dissatisfied when we meet goals — that is the evolutionary motivation to do the next big thing — but the result is often cumulating disappointment. Year after year of finding success less fulfilling than we expected makes us pessimistic about ever attaining satisfaction. So we are simultaneously disappointed in the past and gloomy about the future.

Remember, the happiness curve is only one of factors shaping life satisfaction. People who face painful hardships may feel unhappy, but at least they will know why. By contrast, if you are a successful professional with everything to be grateful for, feeling disappointed in middle age will make no sense to you. Like Simon, you may blame yourself.

Or you may invent something to blame. When people feel dissatisfied, they naturally seek a reason. But human beings turn out to be quite poor at attributing our unhappiness, and we face a special challenge with midlife malaise, because although it is often an artifact of the aging process, it nevertheless feels as if it must be about something.

High-achieving professionals tend to make a heavy emotional investment in their careers. Faced with inexplicable discontent, they may do what Simon does (and what I did), namely fantasize about throwing away their job and starting life anew.

As if all of that were not enough, high-achieving professionals face social pressure to seem masterly and invulnerable, especially in their 40s and 50s, at or near the supposed peak of their career. If they are feeling restless, dissatisfied, or trapped, they often tell no one, not even their spouse. But isolation only makes the problem worse.

And so successful professionals get hit from three sides: Their success makes an age-driven midlife slump both conspicuous and baffling; they mistakenly blame the slump on their careers, and they hide their feelings. Each of those tendencies can reinforce the others.

Three steps to take to get past the bottom of your happiness U-curve

How to cope, if you or someone in your life is struggling in these coils?

First, reaching out to friends, mentors, and coaches does not come easy, especially to high achievers who worry about showing vulnerability, but it can really help. Isolation is not your friend.

Second, beware of disruptive change, because age-driven malaise simply accompanies us to the next place. Change may be warranted in midlife (as at any other time), but make it logical and incremental, building on proven strengths and accumulated connections. Step, don’t leap.

Third, be patient. Often, the best thing to do is the simplest. Wait it out. As we age past midlife, our expectations, our values, and even our brains readjust in ways that help us find new heights of contentment in our 50s, 60s, and beyond.

Finally, be reassured. If you have feelings like Simon’s, there is nothing wrong with you. You are passing through a natural, albeit unpleasant, transition. On the odds, you will be surprised by the rebirth of contentment that lies around the bend.

Jonathan Rauch, a senior fellow at the Brookings Institution, is the author of The Happiness Curve: Why Life Gets Better After 50, just published by St. Martin’s press.