Nothing like hunting for some good will to discover the perfect Saturday Night Live sketch. Or maybe not.

In SNL‘s new promo starring this week’s guest host Matt Damon, The Odyssey star revisits his past in an effort to help cast members Jeremy Culhane and Sarah Sherman come up with the ideal SNL bit. They’re all standing at a Good Will Hunting-style chalkboard illustrated with some very complicated comedy equations.

“Experts have been trying to crack this for years,” Sherman tells a curious Damon, with very serious Culhane adding, “Yeah, Farrell got close once but ultimately it drove him insane.”

When Damon recognizes their chalkboard method from the nearly 30-year-old movie, neither of the young cast members know what he’s talking about. “Never seen it, dude,” says Sherman. “Grew up in a cult, never seen a movie,” says Culhane.

Left alone, Damon takes to the chalkboard like a pro, but the results are not quite up to his old standards.

Watch the the promo above for the janitorial payoff.

Damon returns to SNL for his third time as host on May 9 with musical guest Noah Kahan for his second go-round. Oscar winner Damon next will be seen in Christopher Nolan’s The Odyssey, which hits theaters July 17. Grammy nominee Kahan’s fourth album, The Great Divide, will be released April 24.

An apparently insane Ferrell, incidentally, returns for his sixth time as host on season 51 finale May 16, with Paul McCartney, returning for his fifth time as musical guest.