It seems that even after working together for more than five decades, Elton John and Bernie Taupin can still surprise each other.

In a new interview posted on Elton’s Instagram to plug the upcoming Honky Chateau reissue, he said that “Rocket Man” was “a pretty easy song to write a melody to because it’s a song about space so it’s quite a spacious song.”

Then Taupin explained the actual inspiration for his lyrics. “It was actually a song inspired by Ray Bradbury from his book of science-fiction short stories called The Illustrated Man. In that book, there was a story called ‘The Rocket Man,’ which was about how astronauts in the future would become sort of an everyday job…so I kinda took that idea and ran with it.”

Elton responded, “Do you know, I never knew that.”

Honky Chateau 50th Anniversary Edition is due out Friday.