Chaz Bono

In his first interview since announcing he would undergo a sex change, Chaz Bono says he's enjoying the life he fought for years to attain.

Chastity Bono undergoing gender change

"It's a long process going back almost a decade," Bono told Entertainment Tonight. "I got clean and sober in 2004 and I couldn't have done this before that."

The 40-year-old Bono — who was born Chastity, the daughter of Cher and Sonny Bono — said the most difficult part of the journey was "finding the courage not to worry about what other people would think of me so much."

Bono said he has mentally and emotionally felt he was a man since he was a child. "There wasn't much feminine about me," he said. "I believe that gender is something between your ears, not between your legs. That is something I discovered in the early '90s. It was just a long process of being comfortable enough to do something about it."

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Bono began the sex change in March, and he's already experienced physical changes. "It lowered my voice," he said. "Fat redistributes, muscle growth, hair growth, sex drive increases."

Bono said he's glad he finally moved forward with the sex change, which was finally inspired by turning 40. "I thought it's now or never," he said. " I want to still feel vibrant and be able to enjoy my life in a male body and not wait until I am an old man."