Seth Rogen 'Did a Ton of Acid and Then Went to the Grateful Dead Show' and Now They're His Favorite Band Ever

Seeing a Grateful Dead concert in Las Vegas while on acid made Seth Rogen a lifelong fan.

The Sausage Party: Foodtopia star sat down with Jimmy Kimmel Live! fill-in host Kathryn Hahn, where the two reminisced about their two-week stay in Sin City while filming upcoming Apple TV+ show The Studio—and a fateful concert.

During the second week, Rogen noticed that the Venetian, where he was staying, was filled with "bald men with ponytails and tie-dye shirts." The Dead and Company, a band that consists of former Grateful Dead members and additions like John Mayer, were performing at the Sphere. Rogen caught the show on acid, and not only had the trip of a lifetime, but fell in love with the Grateful Dead's music.

"We were like, 'Oh, the Grateful Dead is here,'” Rogen joked around the three-minute mark about seeing the bald men out and about. "So I can't speak for everyone, but I did a ton of acid and then went to the Grateful Dead show with everybody and with you, and it blew my goddamn mind."

"It really did!" Hahn replied. Rogen added, "It was really something."

"I didn't know any of the music and I danced the entire time," Hahn continued.

"It’s weird to hear a band for the first time and then [they] become your favorite band of all time," Rogen said with a laugh. "I don’t know this song, but it’s the best song I’ve ever heard in my entire life."

Acid, also known as LSD, goes hand-in-hand with the Grateful Dead, originally known as the Warlocks, as the legendary band took part in Bay Area acid test experimentation parties during the 1960s. The parties made for improvisational concerts, and the band would even trip themselves.