- T.S. Spivet: The amazing thing about water drops is that they always take the path of least resistance. For humans it's exactly the opposite.
- Dr. Clair: A fool, by definition, is one who turns what is beyond his mental grasp into one big joke.
- Smithsonian President: Only two things are infinite: the universe and human stupidity and I'm not sure about the former - Albert Einstein
- T.S. Spivet: How beautiful the sun when newly risen, and explodes in the morning greetings happy as the man who can lovingly salute its rising more glorious than a dream.
- [first lines]
- T.S. Spivet: [narrating] Our ranch was located several miles north of Divide, lost in the Pioneer Mountains. The closest thing to traffic was when Union Pacific Freight trains rumbled through the valley. at 5:44 AM, 11:53 AM, 5:15 PM. The Divide was literally located on the continental divide. To the east, rivers spill into the Atlantic. To the west, it spilled into the Pacific. One day my brother Layton and I decided to christen its natural border.
- Layton: [riding atop an oil rig] Giddy up little donkey, yee ha! Giddy up horse, yeah! Ya hoo!
- Layton: Angela Ashworth says AIDS are bad and I probably have them.
- Dr. Clair, Mother: Well! Next time, you just tell Angela Ashworth, just because she feels insecure about being a little girl in a society that puts an inordinate amount of pressure on women to live up to some physical standard, it doesn't mean that she has to take out her misplaced self-loathing on a nice little boy like you. You may be an inherent part of the problem, but it certainly doesn't mean you have AIDS.
- Layton: I'm not sure I can remember all that.
- Dr. Clair, Mother: Well, then just tell her... she's fat.
- Layton: OK.