The 41st president said the affair helped him deal with the stress and pressure he was feeling while he was the commander-in-chief.
“Everybody’s life has pressures and disappointments, terrors, fears of whatever,” he said in the documentary, which began streaming Friday. "You feel like you're staggering around, you've been in a 15-round prize fight that was extended to 30 rounds and here's something that will take your mind off it for a while, that's what happens."
Clinton said he's not defending what he did, adding he feels horrible for it and he's a different person today.
Clinton said he originally lied to his family about the affair, but he eventually sat them down and explained everything.
“I could not believe it," Hillary Clinton said. "I was so personally just hurt and I can’t believe this, I can’t believe you lied."
Bill Clinton also claimed he feels awful about how the scandal has affected Monica Lewinsky since then.
"I feel terrible about the fact that Monica Lewinsky's life was defined by it, unfairly I think," he said. "Over the years, I've watched her trying to get a normal life back again, but you've got to decide how to define normal."