Doc: Well, good luck. For both our sakes. See you in the future.
Marty: You mean the past.
Doc: Exactly!
Marty: You mean the past.
Doc: Exactly!
Doc : Well, good luck. For both our sakes. See you in the future.
Marty : You mean the past .
Doc : Exactly!
http://www.moviequotedb.com/movies/back-to-the-future-part-iii/quote_43464.html