"The best years are behind me"

The sigh has a version that's about age rather than about any particular year. You're forty-eight, or fifty-five, and the shape of life seems clear. It went up, it peaked, and now it goes down, and the good old days were the peak.

David Blanchflower and Andrew Oswald, in 2008, looked at wellbeing across the lifespan in data on around half a million people in America and Western Europe, with a method designed to separate the effect of age from the effect of which generation someone was born into. What they found, on average and holding other things constant, was not a peak and a decline. It was a U. Wellbeing was relatively high in youth, fell through the thirties and forties to a low point in middle age, and rose again after. They found the same shape in Eastern Europe, Latin America and Asia, in seventy-two countries, and in measures closer to clinical ones, including reported depression and anxiety in a million people in the UK.

I'd hold this loosely. It's an average over a great many lives and yours is one life. Later researchers have argued about the shape and the notes say so. But the finding is worth putting next to the sigh, because the sigh is a forecast and the forecast is a straight line down, and the best evidence on the average shape of a life doesn't draw that line. It draws a dip and a rise. And the dip, if you're forty-eight, is roughly where you're standing.

Here's what that means for the golden version. The years you're mourning may be higher than now on the curve, and now may be the low point, and the sigh may be reporting a real difference. But the sigh's second half, that nothing later will match it, is being made from the bottom of a U by someone who can't see the other side. People in their sixties and seventies, on average, report wellbeing that people in their late forties would be surprised by, and the people in their late forties don't believe it, because from where they're standing the only visible direction is back.

I'm not promising you a happy old age. Some lives don't follow the average, and illness and loss can take the curve anywhere. What I'm saying is that "the best years are behind me" is a claim about the future made with a very specific bias, from a very specific point on a curve, and that the evidence on the curve doesn't support the shape the sigh assumes. The best years might be behind you. On the average, they're not, and the person saying they are is standing in the one place the view is worst.