Even if you are on the right track, you'll get run over if you just sit there.
Source: In 1,911 Best Things Anybody Ever Said, ed. Robert Byrne, 1988.
-- Will Rogers, (Nov 4 1879-1935), US actor, lecturer, humorist; He is remembered as a Comedy roper in Ziegfield Follies and a witty columnist, 1926-35.