I've heard that, I recall it was just a response to the "what do you want to be when you grow up" question that every kid gets asked.
Given all the things birhers claimed to have "heard" that has turned out to be not true, that leads me to believe you never really heard it, or that whoever you heard it from just made it up.
Here is a citation of young Barry dreaming of becoming the PM of Indonesia. No need to provide it to the SP. He demands a link, and then dismisses anything you give him. I speak from experiences.