The Con Air actor admits he was a hellraiser in his youth and often trashed hotel rooms and insulted his co-workers on set, and he admits he would have ended up in jail if he hadn't channelled his anger into acting.
Cage is adamant his life was turned around after a heart-to-heart conversation with Gere when they worked together on 1984 movie The Cotton Club.
He tells Britain's The Sun, "I wish I had not been so angry at 18. I was a pretty wild guy with a lot of energy. I was into punk rock and didn't know where I was fitting in.
"I wanted that energy to go somewhere. I wanted it to be constructive rather than destructive, but I just did not have a clue in which direction to take it. Finding a career in which I could express those feelings was lucky. It could have gone either way. I could have ended up in jail... Richard Gere... said to me, 'If you keep on behaving as you are, you will only have about three film roles left in you.'
"I was so gung-ho (reckless). I was ripping up my trailer, trashing my hotel room, walking on set and insulting everyone... So another thing I wish I knew at 18 is that manners are very important and being polite costs nothing. Being angry is a waste of valuable energy."