After his 22-year tenure as the host the Late Show, there was almost nothing that could bring David Letterman out of his well-deserved retirement. Except for, apparently, former The Apprentice host and current dried apricot Donald Trump.

“I have no regrets. None. I was happy,” Letterman told the crowd at San Antonio’s Majestic Theatre on Friday. “And then a couple days ago Donald Trump said he was running for president. I have made the biggest mistake of my life, ladies and gentlemen.”

As the special guest of performers Martin Short and Steve Martin, Letterman came on stage to deliver one last Top Ten List dedicated to the frog-mouthed cheddar golem.

“A lot of people think we would know everything by now about a man, Donald Trump, a high profile fellow,” said Letterman. “But take a look at the list I have here tonight: Interesting Facts About Donald Trump.”