As a sage once said, a wise driver does not depend on his brakes, particularly if he himself has been responsible for their maintenance.
22.09.2011 - As a sage once said, “A journey of a thousand miles begins with one step.”
If war begins, as a sage once said, in the minds of men, then it is in the minds of men that seeds of peace must be sown.
etc.
---"sage" (#2) is pretty commonly used; on the other hand, while "sage" doesn't explicitly say "man," it does tend to have been used in particular of men; OED includes "man" in its definition of the noun, M-W Unabr. doesn't.
(I'd prefer, as in the examples above, the form with "As ..." + comma + quote rather than the colon so often used in G., but ultimately context decides.)
