Who said "The saddest words a man can hear are: 'You could have been.'"?

This quote is attributed to Charles Foster Kane.

The saddest words a man can hear are: 'You could have been.' - Charles Foster Kane

"The saddest words a man can hear are: 'You could have been.'"

Charles Foster Kane

"I am, by any practical definition of the words, a self-made man."

"You know, Mr. Thatcher, at the rate of a million dollars a year, I'll have to close this place in sixty years."

"I think it would be fun to run a newspaper."

"I could have been anything you like. Perhaps I could have been a builder of cathedrals."