The singer said he was so ambitious that he started having panic attacks at the age of 12.
"I needed to know my life plan. There's always been a hunger in me not necessarily to be successful, but to be an icon," he told GQ.
Smith, 22, says he is a "bossy older brother" and "very paranoid and secure all the time".
The singer once again talked about being different from other pop stars.
"I envy the competition that people like (Frank) Sinatra would have had - you know, the people that he'd be standing on the stage with - because you could tell he was working off them. I need a Rat Pack, I really do," he said.