When it comes to human foibles, there isn't much that aging doesn't cure.

Most of us eventually grow out of all that petty self-puffery — the vanity, pride and arrogance of youth.

But narcissism is a tough nut to crack. It's self-love gone to extremes. How do you fall out of love with your smartest, funniest, best-looking friend in the whole world?

It turns out, even that relationship starts to crack as we get older.

According to researchers at the University of Illinois, most narcissists figure out by their early 40s that they're not entitled to all the success and attention in the world. They may even start leaving some for the rest of us.

The study, published this month in the Journal of Personality and Social Psychology, tracked the lives of 237 people from the age of 18 to 41, all showing various levels of narcissism.

And how do you spot a narcissist? It's not as hard as you might think. For starters, do you know anyone who has an exaggerated sense of self-importance? Or maybe someone who craves constant attention and admiration? In fact, there are nine symptoms psychologists use to diagnose someone with Narcissistic Personality Disorder. A classic narcissist checks all the boxes, while someone with varying degrees of it will typically hit five.

For their study, researchers interviewed participants when they were freshman at the University of California, specifically noting levels of vanity, belief in their leadership skills and sense of entitlement.

In other words, they recorded their insufferability score. As time wore on and participants got more acquainted with life's realities, they reported lower scores for narcissism.

By the time they reached 41, most of them were cured. Or, at least, a lot easier to be around.

And that probably comes as welcome news to people who think some generations are irredeemably self-absorbed and likely to make a mess of the world.

"The findings should bring comfort to those who are concerned that young people are problematically narcissistic," study co-author Brent Roberts, a psychology professor at the University of Illinois, notes in a press release. "With time, it seems most people turn away from their earlier narcissistic tendencies."

When you finally learn it's not all about you

A woman looks at her reflection while out to coffee with a friend Narcissistic people are usually focused more on themselves than the people around them. (Photo: Peter Bernik/Shutterstock)

The prescription for chronic self-love turns out to be age, and as researchers noted, a regular dose of suffering. Indeed, narcissists may even suffer more than others.

The study notes that participants who showed higher level of vanity when they were 18 were more likely than others to experience rocky relationships and marriages. By middle age, they were more likely to have had at least one divorce.

Those in the study who ranked high in a sense of entitlement in their youth also reported more negative life events. Narcissism, it seems, takes a lifelong toll, as the experience wears down even the most devoted self-worshippers.

Surprisingly one facet of narcissism — the belief in one's own leadership qualities — also flagged as people got older. It's considered the least pathological element of narcissism and a quality researchers expected to increase over time.

"We know from past research that another component of personality — assertiveness — tends to increase during this time of life," Roberts explains.

"So, I thought it was reasonable to hypothesize a similar increase in the leadership facet. This either means the past research is wrong, or our read of the leadership component of narcissism is wrong — it may actually be more negative than we thought. We have to figure this out in future research."

We may also have to figure out what to do with the people 3% of participants who remained unshakably in love with themselves. A few people even doubled down and got more narcissistic over time.

"Some remained just as narcissistic at age 41 as they had been when they were 18 years old," notes study co-author Eunike Wetzel of Germany's Otto-von-Guericke University.

Then again, maybe it's not a question of what to do with them so much as how to avoid them.

Narcissists fall out of love with themselves as they get older
A new study tracks more than 200 narcissists from the age of 18 to 41.