U.S. market has "improved radically": Bogle

"I live life one day at a time," he said. "When my mind gets bad, I hope that somebody, my wife maybe or somebody here, will say 'you are not the man you used to be'."

"And, of course, I'm not in terms of physical strength and endurance and all that. But I think in terms of moral strength, writing strength, intellectual strength, I am as good as I am going to get," he added.

(Editing by Leslie Gevirtz)