The milkshake line from There Will Be Blood came from a transcript that PT Anderson found of the 1924 congressional hearings over the Teapot Dome scandal.
Anderson concedes that he's puzzled by the phenomenon — particularly because the lines came straight from a transcript he found of the 1924 congressional hearings over the Teapot Dome scandal, in which Sen. Albert Fall was convicted of accepting bribes for oil-drilling rights to public lands in Wyoming and California.
In explaining oil drainage, Fall's "way of describing it was to say 'Sir, if you have a milkshake and I have a milkshake and my straw reaches across the room, I'll end up drinking your milkshake,' " Anderson says. "I just took this insane concept and used it."
(via observations on film)