The 41-year-old star - offspring of singing legend Cher and the late Sonny Bono - underwent gender re-assignment surgery in 2009 and legally became a man last year and says it was the best the thing he`s ever done because he finally feels happy with himself. Speaking in his new documentary `Becoming Chaz` - which gives a personal insight into his female-to-male transition - he said: "It`s the greatest thing I`ve ever done in my life. It’s the only time I`ve felt like a complete person." Although he was born a female called Chastity, Chaz says he wanted to be a boy from a very early age and never felt comfortable in his own skin. He said: "I`ve hated my body since puberty. "When I was a little girl, I would go to sleep at night praying I`d wake up as a boy. I just knew I wanted to be a boy." Chaz - who came out as a lesbian aged 18, and now lives in Los Angeles with Jennifer Ella, his girlfriend of five years - says he decided to do a documentary about his experiences to help other people. He said: "I wanted to do this because I wanted to help people. And I knew that I could put a face on this issue that people just don`t understand because it`s a hard one to understand. I wanted to be able to change people`s hearts and minds on this."