David Crosby says that his drug addiction remains the biggest regret of his life. The new doc, David Crosby: Remember My Name was helmed by first time feature-doc director A.J. Eaton and produced by Cameron Crowe. Crosby told People that Crowe knowing him intimately for years -- and witnessing him in every kind of condition -- ensured the film would cut deep and stay honest, explaining, "Cameron has known me for a long time and he knows where all the bones are buried. He knows what happened because he was there. He was there in the dressing rooms and backstage with us for years. He watched me go down the tubes as a junkie. He watched me slowly climb back out of the dung pile. He asked me the hardest questions I've ever been asked and I answered. I did the one thing that they asked me to do to contribute to this film, which was not lie."

Crosby spoke frankly about his nearly fatal freebasing and heroin addiction, admitting, "It cost me probably 10 years of my life. I regret it greatly. If I had to change one thing, that would be it. No hard drugs, because it nearly killed me and put me in prison and, most importantly, it kept me from making music."

He went on to say, "I'm trying to be honest. I know what I am and I know that I'm difficult to deal with, and I know that I have certainly offended many people. I am opinionated and sometimes I may possibly shoot my mouth off. . . I get in trouble, but I'm happy about myself now."

Crosby, who turns 78 next month, battles a spate of health issues, but remains committed to making a difference both in the studio and on the road, saying, "It's the one contribution I can make. See, it's dark out here now. The world is not a happy place. Music's a lifting force. Music makes things better."

It's been over 33 years since a clean and sober David Crosby was released from a Texas prison after serving an eight-month stint for weapons and drug possession. Crosby said that any way you cut it, drugs are a dehumanizing and losing game: "I love music, man. I kept it real important. But anyone that tells you you can do it and do drugs; send 'em to me. I'll talk to them. It's not true. It's the only terminal illness that tells you you're fine! If you have the guts to kick it, you will get everything you really wish you had."

AUDIO: DAVID CROSBY ON ADDICTION