Have you been watching this last leg of David Letterman shows as the late night king prepares to retire next month? If not, you're missing out. It's classy send-off after classy send-off, and Tuesday night, Michael Keaton decided to swing back by to say goodbye to his old pal from the comedy club circuit. We're a few months removed from the “Birdman” star losing the Academy Award to “The Theory of Everything” star Eddie Redmayne on Oscar night, and he had a few thoughts on that, it turned out.

Keaton told a story about being at the Academy Nominees Luncheon in February and a distinguished industry vet gushing about his performance in Alejandro González Iñárritu's film, which itself went on to win four Oscars including Best Picture. “I thought to myself, 'Psh, I am a lock…That's about it. That's all I need!'” he recalled. “And as I get up he says, 'Just remember, Michael, when it comes to winning an Academy Award, illness always wins.' And I thought, 'I am so f**ked right now.' I went from 'This is a done deal' to 'I'm done!'”

I'm sure there will be those who take that as a slight to Redmayne, but whatever. Letterman, by the way, commented on Keaton's loss following the Oscars by feigning bewilderment over a film winning Best Picture, Best Director, Best Screenplay but not Best Actor.

Check out the clip below. And seriously, watch these last episodes. It's the end of an era.

[youtube https://www.youtube.com/watch?v=fdVtY_auxcA]