Christoph Waltz sings the saddest 'Sesame Street' theme ever

Apparently, Christoph Waltz didn't watch the same Sesame Street that we did as kids.

On Tuesday's Jimmy Kimmel Live, when Kimmel wasn't showing clips of the Horrible Bosses 2 star in a

singing about the new year for an Austrian children's TV show, he was asking him about watching the American children's show, which Waltz says got dubbed into German for Austrian viewers.

Waltz, perhaps best known to American audiences for his roles in Quentin Tarantino films like Django Unchained and Inglourious Basterds, says he had his kids watch the show because he felt they would need to be Americanized at some point. Besides, he appreciates the show, even as an adult.

"It's so trenchant," he said. "It's raw. It's full of despair. It's poignant, deep."

Wait ... what?

"The theme song alone, it haunts me."

Waltz then sang the song for Kimmel. If you watch it, it may haunt you, too.