Los Angeles, Dec 3 (IANS): Actor Will Smith says he was inspired to become famous by a girlfriend who cheated on him when he was just 15.

"When I was 15, my girlfriend cheated on me. And from that moment, in this bizarre psychological twist, I wanted to be the most famous entertainer on Earth," Smith told variety.com.

While Smith suffered heartbreak in his youth, these days he could not be any happier with his wife, and says the key to a long lasting marriage is never to give up.

"We've been married for 20 years and we've been asking ourselves (what's the secret to marriage) and really at the end of the day it's just not quitting. You can't expect it to be easy, it's like our marriage was the most difficult, excruciating thing that we have ever taken on in our lives. And, you know, we're just not quitters," he said.

"We only ever worked on ourselves individually and then presented ourselves to one another better than we were previously," Smith added.