Jerry Seinfeld is a world-famous comedian, he starred in one of TV’s most beloved sitcoms, and he’s got a $100 million deal with Netflix. But as he explained at the New Yorker Festival on Friday night, nothing in his long career tops his 2015 episode of Comedians in Cars Getting Coffee with Barack Obama. “It was the greatest moment of my life,” he told New Yorker editor David Remnick during the event. “Who gets to do that?”

The experience was also plenty nerve-wracking, he said, comparing the feeling to his jitters before his first-ever appearance on The Tonight Show With Johnny Carson. “It was absolute, sickening nerves. It seemed like a once in a lifetime opportunity, that I’m gonna get to be funny with a president in the White House.”

Would Seinfeld ever repeat the experience with Donald Trump? Don’t count on it. “Please no,” he told Remnick. “You have to have some kind of comedic credential to get on that show.” And if Trump did somehow wind up coming along for a ride, Seinfeld wouldn’t want him to crack a smile. “My friend Colin Quinn said to me this morning, ‘Trump’s happy face, that’s his scariest face.’”

In his stand-up routine, though, Seinfeld says he has no room for politics. “It has no shelf life,” he explained. “Political jokes are so much more based on the political moment that you’re making fun of, as opposed to some really inventive joke structure,” he said. And for a comedian like Seinfeld, a joke’s structure and logic is paramount — so much so, he noted, that he once spent seven years perfecting a bit about a tuxedo.