Humility, it is sometimes said, doesn’t mean thinking less of yourself. It means thinking of yourself less.

For Carli Lloyd I’d guess that’s a distinction without a difference. After Lloyd scored the goals that lifted the US Olympic women’s soccer team to a 2-1 victory over Japan in the gold medal match at London’s Wembley Stadium last week, thinking of herself less was decidedly not on her agenda.

“When someone tells me I can’t do something, I’m going to always prove them wrong,” Lloyd bragged to an NBC interviewer. “That’s what a champion is all about and that’s what I am – a champion!”

Once upon a time it was considered low-class for athletes to be so smug and self-adoring. Winners of championships and gold medals were expected to be gracious, to show a little modesty – to enjoy the acclaim their splendid achievements had earned, without becoming boastful jerks in the process. At times the taboo extended even to the impression of arrogance: For merely failing to tip his cap to fans at Fenway Park, Ted Williams was thought by many to be haughty and too full of himself.

Of course many gifted athletes are still models of grace and good manners. But as viewers of the recent Olympics were too often reminded, the egotists who aren’t not only pay no penalty, they are showered with attention and air time.

“I’m now a legend,” crowed Jamaican sprinter Usain Bolt, who won gold medals in the men’s 100- and 200-meter races at the London Games. “I’m also the greatest athlete to live.” Humility? What’s that? Well before the Olympics opened, Bolt was swaggering for the press, telling reporters in June that the London Games would make him a “living legend.”

Michael Phelps steered clear of Bolt’s spotlight-seeking antics, but he too reached for singularly immodest language after winning his 22nd Olympic swimming medal. “You know what, I’ve been able to become the best swimmer of all time,” he said, describing his successful drive to become the Michael Jordan of swimming. “I did everything I wanted to.” Team USA basketball star Kobe Bryan, meanwhile, publicly insisted not only that he was “the best post player on this team, period,” but that there was nothing he could learn from his teammates.

In some quarters, this flood of self-worship is applauded as healthy and honest. “The most satisfying part of Bolt – even more than his brilliant runs – is how much he demolishes the myth that the world wants humble athletes,” writes sports columnist Jason Gay in The Wall Street Journal. Those who object to Bolt’s strutting braggadocio, Gay suggests, are “the kind of people who hate pizza and scream at dogs.”

But even in a society fixated on fame and self-esteem, there is nothing admirable about anyone whose first instinct is to sing his own praises. To be sure, showboating narcissists can go far in the world. They may amass money or power or star in their own reality show. Yet an exaggerated sense of self-importance is not the same as greatness. No one can be great who can’t be humble, and humility begins with the understanding that it’s not all about you.

It is often remarked that recipients of the nation’s highest military decoration invariably insist that they don’t deserve any glory. Sergeant 1st Class Leroy Petry, a US Army Ranger, last summer became only the second living soldier since the Vietnam War to receive the Medal of Honor. During a harrowing firefight in Afghanistan, he had saved the lives of at least two men in his unit by lunging for a grenade before it could kill them. It exploded in his hand, catastrophically amputating it.

Yet Petry doesn’t trumpet his heroism or brag about his courage. “It’s not courage,” he says. “It was love. I looked at the two men next to me that day and they were no different than my own children or my wife. I did what anyone would have done.” Usain Bolt and Carli Lloyd flaunt their Olympic gold and tell the world how great they are. Sgt. Petry, humbly deflecting the spotlight, comes closer to greatness than they ever will.

An old Jewish tradition teaches that God chose to reveal the Ten Commandments on lowly Mount Sinai, not a soaring peak, in order to link greatness with humility. None of us is so amazing that he couldn’t stand to be more humble. Self-esteem has its place, but it also has its limits. Even in the age of Facebook – even on the Olympic medal podium – swelled heads aren’t very attractive.

(Jeff Jacoby is a columnist for The Boston Globe. His website is www.JeffJacoby.com).