The actor/singer grew up poor and hungry, surrounded by gang violence, abuse and alcoholism, and he admits he has never met anyone who had a worse upbringing than he did.
He tells U.S. news show Access Hollywood, "My childhood was probably one of the worst childhood experiences ever. You're talking about gangs and prostitution, drugs and physically being there witnessing murders happening and my mom being alcoholic for seven years, so nothing about my childhood was easy.
"My neck used to hurt because I used to walk, like, two miles to get to the bus stop. It was a bus called the Dash that only cost a quarter. The Rtd (Rapid Transit District bus) was about a dollar 35 (and) I definitely didn't have that. My neck was hurting because I would walk from my house all the way to the bus stop, hoping that I'd run into some change on the way to the bus stop, trying to get to school."
Gibson reveals he has since addressed his childhood problems in therapy and he now realises that the feelings of hunger he experienced as a kid are what fuelled his drive to study and eventually succeed.
He adds, "I was hungry all the time and I had a problem with being hungry and not being able to eat... There was food at school; there's breakfast and there's lunch."
Gibson also found a mentor in a music teacher called Reggie Andrews who encouraged the young singer to join his after-school program, where he was fed.
He went on to win a talent contest at 14 and, with his new-found confidence, he started calling record labels looking for a deal. His perseverance paid off when a temp agreed to meet him and check out his singing skills.
Gibson adds, "She changed my life. It takes one person to believe in you and she did. And here I am, on Access Hollywood."