In their study comparing the memory of young and old Chinese and Americans, Ellen Langer, a social psychologist, and Becca Levy, an epidemiologist, found that the older Chinese people, who, it was hypothesized, were exposed to less ageism than their American counterparts, performed memory tests more like their younger compatriots. Among the Americans, on the other hand, there were significant memory differences between the old and young. The beliefs that we imbibe about our waning powers may turn out to be self-fulfilling. In effect, our culture teaches us how to be old.

The historians Thomas R. Cole and David Hackett Fischer have documented how, at the start of the 19th century, the idea of aging as part of the human condition, with its inevitable limits, increasingly gave way to a conception of old age as a biomedical problem to which there might be a scientific solution. What was lost was a sense of the life span, with each stage having value and meaning.

Perhaps this is why, as a 2006 study found, we mispredict the happiness we expect to feel across the course of our lives and assume that we’ll get more unhappy as we age. In fact, the research shows that the opposite is true. For my part, at 64, I haven’t attained serenity (another stereotype of older people), but I am more able to savor life — and if offered the chance to return to my 14-year-old self, I’d run screaming the other way.

A student of mine, nudging 60, recently called age “the great liberator.” Part of what she meant was that old people simply care less about what others think, but also, I think, that our sense of what’s important grows with age. We experience life more intensely than before, whatever our physical limitations, because we know it won’t last forever.

How to enable the growing numbers of old people to live comfortable, meaningful lives is a fundamental issue of equality, with benefits for all. If we make the world better for old people, we make it better for everyone, from stroller-pushers to wheelchair-users.

Maggie Kuhn, the founder of the elder advocacy organization the Gray Panthers, argued that instead of making a fetish of independence, we should value the idea of interdependence between generations. Thus age-friendly cities, like Portland, Ore., rethink urban spaces to make them more accessible and encourage the integration of old people into communal life. And programs like Cleveland’s intergenerational charter schools, which provide lifelong education alongside grades K-8, break down the age apartheid now so common. Instead of seeing each other as generic categories, old and young people can discover each other as individuals.

Age resistance is a futile kind of life resistance: We can’t live outside time, we begin to age the moment we’re born. But the emerging age-acceptance movement neither decries nor denies the aging process. It recognizes that one can remain vital and present, engaged and curious, indeed continue to grow, until one’s dying breath. Then we need only echo the wish of the British psychoanalyst D. W. Winnicott: “May I be alive when I die.”