Dr. Emmett Brown: Tell me, "Future Boy", who's President in the United States in 1985?
Marty McFly: Ronald Reagan.
Dr. Emmett Brown: Ronald Reagan? The actor? Then who's Vice President? Jerry Lewis? I suppose Jane Wyman is the First Lady!
Marty McFly: Whoa! Wait! Doc!
Dr. Emmett Brown: And Jack Benny is Secretary of the Treasury.
Marty McFly: Wait a minute, Doc, are you trying to tell me that my mother has got the hots for me?
Dr. Emmett Brown: Precisely.
Marty McFly: Whoa, this is heavy.
Dr. Emmett Brown: There's that word again; "heavy." Why are things so heavy in the future? Is there a problem with the earth's gravitational pull?
Marty McFly: [watching a Honeymooners episode in 1955.] Hey, hey, I've seen this one. I've seen this one. This is a classic. This is, uh, where Ralph dresses up as a man from space.
Milton Baines: What do you mean, you've seen this? It's brand new.
Marty McFly: Yeah, well, I saw it on a...rerun.
Milton Baines: What's a rerun?
Marty McFly: You'll find out.
Dr. Emmett Brown: This sucker's electrical. But I need a nuclear reaction to generate the 1.21 gigawatts of electricity I need.
Marty McFly: Doc, you don't just walk into a store and buy plutonium. Did you rip that off?
Dr. Emmett Brown: Shhhhhh. Of course. From a group of Libyan nationalists. They wanted me to build them a bomb, so I took their plutonium and in turn, gave them a shiny bomb-casing full of used pinball machine parts!
Dr. Emmett Brown: Now, remember - according to my theory, you interfered with your parents first meeting. If they don't meet, they won't fall in love, they won't get married and they won't have kids. That's why your older brother's disappearing from that photograph. Your sister will follow, and unless you repair the damage, you'll be next.
Marty McFly: Sounds pretty heavy.
Dr. Emmett Brown: Weight has nothing to do with it.