The 48-year-old superstar spent most of his interview on US TV's Inside the Actor's Studio being his usual zany self.
But he could not hide his emotions as he spoke of the traumatic childhood when his dad was made unemployed and he went from a middle class upbringing to one of complete poverty. He recalled growing up in Newmarket in Ontario, Canada.
'My father lost his job when he was 51 - I was 12 - and that was the real 'Wow', the kick in the guts,' he said. 'We lived in a van for a while, and we worked all together as security guards and janitors. I was going to school, and after school I was doing an eight hour day in a factory.'
Carrey says he went from being a 'straight-A student to not wanting to know anybody's name, and not wanting to make a friend'.