In a new clip for Season 3 of Netflix's My Next Guest Needs No Introduction With David Letterman, the veteran late-night host asks Robert Downey Jr. about his time playing Iron Man. Specifically, Letterman is curious to hear about the Iron Man helmet: "When that thing clamps onto your head, is that thing really there? Or is it not really there?" The answer might surprise you--check out the full clip below.

Downey recalls those early, still somewhat uncertain days of comic-book movies--the first Iron Man was released in 2008, still a full year before Marvel Entertainment was acquired by The Walt Disney Company. As such, Downey tells Letterman, "Initially, everything was really there. They wanted to spend as little as they could on CG replacement, so I remember this helmet went on… and it slammed closed, and I couldn't see anything, and then these LED lights went on and it was like The Manchurian Candidate… I was absolutely blinded."

Those humble origins in Iron Man makes it all the more impressive that the many comic-book movies that followed eventually resulted in Avengers: Endgame becoming the top-grossing movie of all time (if you take reported revenue numbers at face value). Earlier this year, Downey said he has no plans or desire to play Iron Man again.