Keanu Reeves once asked Lou Reed for his autograph

Keanu Reeves once asked the "cool" Lou Reed for his autograph.

During an appearance on The Late Show with Stephen Colbert on Wednesday night, host Stephen asked The Matrix actor a series of quick-fire questions as part of a segment called "The Colbert Questionert".

Asked whether he'd ever asked someone for their signature, Keanu recalled how he approached Lou for his autograph on behalf of a friend.

"He was cool about. It was a little piece of paper with blue ink. It was good. (It said), 'Lou Reed.' You never know, it's Lou Reed," he smiled.

Walk on the Wild Side hitmaker Lou died at the age of 71 in 2013.

Keanu then went on to share that he also once asked comedian George Carlin, who passed away in 2008, for an autograph.

"It was really funny, George Carlin... he wrote, 'Dear Keanu, f**k you,'" the 57-year-old laughed. "I always thought he just wrote that for me and then I met someone else who said that he wrote the same thing to them. Anyway, beautiful."