Warren Buffett, 88, and Leon Cooperman, 75, are two of the most successful investors of all time. Buffett, the chairman and largest shareholder of Berkshire Hathaway, is worth a cool $86.6 billion, while Cooperman, the founder and CEO of Omega Advisors, has a personal fortune of about $3.2 billion.

The self-made billionaires both readily admit that they wouldn't be where they are today without good fortune.

Cooperman, who was raised by working-class Polish immigrants and was the first in his family to go to college, said on CNBC's "Fast Money Halftime Report": "Whatever success I've achieved, I think I've achieved it because I've been very lucky." He added that common sense and a strong work ethic have also contributed to his fortune.

And Buffett has often talked about how lucky he's been from the beginning because he won the "ovarian lottery," meaning that he was born with real advantages that helped him get ahead.

"The womb from which you emerge determines your fate to an enormous degree for most of the seven billion people in the world," Buffett told journalist Rebecca Jarvis in 2013. "Just in my own case: I was born in 1930, I had two sisters that have every bit the intelligence that I had, have every bit the drive, but they didn't have the same opportunities."

In short, "if I had been a female, my life would have been entirely different."