Why did Armstrong adamantly deny his use all these years — only to come clean now? “Men in traditional roles — competitive sports, high-pressure finance — are the men who often get tripped up in having to keep a secret,” says Harvard psychologist Dr. William Pollack. “Men are shame-phobic — frightened to death to show shame and feel shame. They’ll go out of their way to deny anything that will bring them shame.” (Do you love yourself a little too much? Discover where confident guys go wrong.)

What are men so worried about? “It’s tied into the codes of masculinity. Men feel like if they are shamed by others, then they’re less of a man,” Pollack says. This is especially true with athletes, Pollack adds, who are expected to always win. It’s an impossible standard, even for the likes of Lance Armstrong — who can convince himself he’s cheating for his fans.

Once men start lying, they can continue by mentally compartmentalizing the truth, Pollack explains. “It’s not really repressed or forgotten; it’s pushed aside because it needs to be.”