The Never Say Never star explained that before he became famous, he and his mother shared a Canadian council flat where he slept on a pull-out sofa.
He recalled: "That place was really dirty. We had mousetraps everywhere because there were mouses - uh, mice - in the house. I didn't have a real bed. I slept on a blue pull-out couch in my room."
The 17-year-old, who is rumoured to be dating Selena Gomez, said that he would like to play poverty-stricken orphan Oliver Twist in a remake of the 1966 musical Oliver! because he can relate to the role.
He explained to The Sun: "We didn't have anything in the fridge, except maybe luncheon meat for school and macaroni and cheese. I'd love to play Oliver Twist."