"Bold" can mean "daring" and "willing to take risks."
The "Jack London Credo" is attributed to Jack London, the U.S. author of "The Call of the Wild" (and some really wonderful short stories). It is a very good expression of "the bold life." Jack London himself definitely led a "bold life" (and a short one, dying at age 40).
I would rather be ashes than dust!
I would rather that my spark should burn out in a brilliant blaze than it should be stifled by dry-rot.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.
The function of man is to live, not to exist.
I shall not waste my days trying to prolong them.
I shall use my time.