“While you have a future do not live too much in contemplation of your past: unless you are content to walk backward the mirror is a poor guide.”
Source: Epigrams, p. 374
Help us to complete the source, original and additional information
Ambrose Bierce 204
American editorialist, journalist, short story writer, fabu… 1842–1914Related quotes

BBC interview, used in a Citroën ad, as quoted in "John Lennon Appearance In Car Ad Stirs Controversy" by Monica Herrera in Billboard (4 March 2010) http://www.billboard.com/column-viralvideos/john-lennon-appearance-in-car-ad-stirs-controversy-1004072693.story#/column-viralvideos/john-lennon-appearance-in-car-ad-stirs-controversy-1004072693.story. Though there has been no official dispute that he made this statement, a YouTube video has claimed that the audio used in the advertisement is not original http://www.youtube.com/watch?v=ipyUk5-wlFg.
Disputed

CBC Documentary: How To Go Out of Your Mind: The LSD Crisis (1966)
Context: We always have urged people: Don't take LSD unless you are very well prepared, unless you are specifically prepared to go out of your mind. Don't take it unless you have someone that's very experienced with you to guide you through it. And don't take it unless you are ready to have your perspective on yourself and your life radically changed, because you're gonna be a different person, and you should be ready to face this possibility.

Paris 1923
As quoted in Futurism, ed. Didier Ottinger; Centre Pompidou / 5 Continents Editions, Milan, 2008, p. 311
Quotes, 1920's

“We look at the present through a rear-view mirror. We march backwards into the future.”
1960s, The Medium is the Message (1967)