TORONTO - Eric Clapton says it's hard to watch himself as a pompous young man in the new documentary "Eric Clapton: Life in 12 Bars."

The guitar legend says he was forced to confront his arrogant youth in the film, which is making its world premiere at the Toronto International Film Festival.

Clapton tells a festival press conference that it's only now that he's older that he realizes he knows "nothing at all."

He says it's been a slow evolution that started when he stopped drinking and had children.

The new film, directed by Lili Fini Zanuck, traces the life of the guitar virtuoso as he builds a career with the Yardbirds, Cream, Blind Faith, Derek and the Dominos, and then as a solo artist.

It features interviews with B.B. King, Jimi Hendrix, George Harrison, Steve Winwood and Clapton's former wife, Pattie Boyd.