"I think acting is a con game," Shia told Parade Magazine in its June 14 issue. "I don't understand what it is I do that people want. I don't know what an actor does. To my mind, talent doesn't really exist."
And the star, who said sometimes he's frightened by feeling like he's living "a meaningless life," doesn't think he's the only one in Hollywood who's less than fulfilled.
"The good actors are all screwed up," he said. "They're all in pain. It's a profession of bottom-feeders and broken people."
In several recent interviews, the star has spoken of his unorthodox childhood – he grew up in poverty in LA's Echo Park neighborhood to "hippie" parents who exposed him early to adult material.
"Seeing my parents have sex, smoke weed, my mom being naked – just weird stuff," he told Parade.
Despite his career insecurity, Shia, 23, had an outlet in acting from a young age, doing stand-up comedy at 10 before joining the Disney Channel's "Even Stevens." He has since made a splash on the big screen, starring alongside Harrison Ford in "Indiana Jones and the Kingdom of the Crystal Skull" and headlining "Transformers," "Disturbia" and "Eagle Eye." The "Transformers" sequel, "Revenge of the Fallen," is due on June 24.
"I know I'm one of the luckiest dudes in America right now," he said. "I have a great house. My parents don't have to work. I've got money. I'm famous. But it could all change, man. It could go away. You never know."
And stardom hasn't been all fun and games for Shia – he injured his left hand in a car accident last year that saw his Ford F-150 flip three times — an accident from which he's still recovering.
"It was smashed so bad it didn't even look like a hand," he said.
And his career, Shia added, has gotten in the way of his love life, contributing to his 2007 split with China Brezner.
"Why did the love of my life and I break up? Man, I have no idea…. Maybe it was career pressure. Maybe I chose work. What I do know is, I screw up, and I know that I'm working on myself to be a better person," he said. "So I have no apologies. The best I can do is learn from my mistakes and move forward. And that's what I'm trying to do."
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