The bassist played with the British singer in supergroup Atoms for Peace - which also included punk singer Patti Smith and Gorillaz frontman Damon Albarn - and said it really helped broaden his musical horizon.
He said: "It influenced me being around Thom. He's an unbelievably great musician and a beautiful man. He's so pure as an artist. It's less that I would try to copy him and more that just being around someone who channels really powerful energy is beneficial.
"It's a relationship I will always hope to nurture."
While he enjoyed playing with the group during the Red Hot Chili Peppers' two-year break after last album 'Stadium Arcadium', he is glad to get back to his "home" with his other bandmates.
He added: "But the Chili Peppers are a different entity. It was inspirational to play with Thom, Damon and Patti but being in a band with Chad [Smith], Anthony [Keidis] and Josh [Klinghoffer] is my home. It's a Beautiful Thing."
Flea and Josh also took tips from Damon, getting involved with his Africa Express project, which involved an emotional trip for the pair to Ethiopia.
Josh explained: "It was like a musical field trip. We had outings every day. It was like Summer Camp - and then Flea got lost and when he was lost, he went through a lot of emotions which is reflected on the album. It's the point where we were starting to really come together."
Part of Flea's experience is recounted in the track 'Ethiopia' on the band's new album 'I'm With You'