It wasn’t long after Diana Nyad emerged from the ocean in Florida after a historic 53-hour, 110-mile swim from Cuba that doubters started to question her record-setting accomplishment.

Was the 64-year old swimmer actually in the water the whole time? Could she have made the crossing as quickly as she claims? With a crew that helped feed her and put on a special jellyfish suit, did her feat qualify as truly “unassisted?”

Fueled by the marathon-swimming community, these criticisms raise larger questions about why onlookers can’t just take Nyad for her word and derive inspiration from an incredible physical feat.

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From topping Mt. Everest to discovering the source of the Nile, nearly every new “first” has been immersed in debate and controversy -- perhaps because it can be hard to believe that someone has done something extremely challenging that others have failed to do before.

In modern times, skepticism has spiked with every new example of cheating, such as the use of performance-enhancing drugs. Even as our culture elevates athletes to superstar status and follows their every move, we are quick to watch them fall from grace and then spread real-time gossip about what happened, said Dan Lebowitz, executive director of the Center for the Study of Sport in Society at Northeastern University in Boston.

“We live in an era of suspicion about anything accomplished,” Lebowitz said. “We get caught up in loving the rise and loving the fall even more. Some of the negative qualities in human nature celebrate the fall more than the feat.”

Examples of discounted athletic endeavors are numerous.

Cyclist Lance Armstrong was long hailed as a national hero with an unprecedented seven consecutive Tour de France wins until evidence that he doped stripped him of his titles and banned him from competitive sports.

Likewise, baseball fans marveled at Barry Bonds’ home-run records until he became wrapped up in a steroids scandal. Same goes for New York Yankees phenom Alex Rodriguez. And Canadian runner Ben Johnson notoriously disappointed spectators who marveled at his 100-meter world records after it turned out that he had doped.

Long-distance swimmer Diana Nyad cheers before jumping into the calm, turquoise waters of Cuba making her way towards home, Key West, Fla.Enrique del la Osa/Corbis

The list of cyclists, runners, swimmers, tennis players, weightlifters, baseball players and other athletes who have unfairly boosted their performance goes on and on. Now, even when there is no evidence that an athlete is cheating, like in the case of the phenomenal Jamaican sprinter Usain Bolt, people wonder. And they wonder out loud.

With around-the-clock, high-speed access to the Internet, rumors can fly quickly, allowing small suspicions to snowball into major news stories. Those doubts are compounded by the extreme pressure we put on our celebrities, including our celebrity athletes.

“We tend to do two things to people in the news,” said Nate Zinsser, a certified sport psychology consultant who works with Olympic and professional athletes and is also director of the sports psychology program at the United States Military Academy in West Point, N.Y.

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“We tend to elevate them to godlike status or we reduce them to dirtbag status,” he said. “If you look at the way the media treats athletes, Lance Armstrong was a god and then he became dirt. I think the truth is probably somewhere in between for everybody.”

Beyond doping scandals, there may also be some inherently insecure side of human nature that causes people to find fault in others as a way to feel better about themselves.

“I can’t prove this, but I’ve seen enough examples of people looking for heroes to inspire them and also for anti-heroes to denigrate,” Zinsser said. “I think there’s a bit of a pull for people to look for the best in others and actually seek inspiration, and then there’s also a pull for people to find other people to look down upon to separate themselves from and think, ‘I’m better than that.’”

As a public figure, Nyad faces the same challenges as every other elite athlete who is constantly under the spotlight of public scrutiny, Zinsser said. To continue being successful in their sports, athletes must learn to cultivate a sense of mental toughness. Internalizing criticism will only sap their energy.

“Quietly on the inside, they have to say, ‘I don’t really care what the rest of the world thinks,’” Zinsser said. “I’m sure Diana Nyad is probably thinking, ‘Well, to hell with those guys. They don’t know what I did. If they want to doubt me, that’s their business. I know in my heart of hearts what I did, and I’m not going to concern myself with what others say.’”

“That’s what great athletes have to do,” he added, “to protect their sense of being special and the best in the world.”