Donnie Darko (2001)

Continuity mistake: When Cherita makes her mark on the lifeline blackboard, there are some smudges on the broad chalk line. In the next shot, the line is perfect again. (00:41:30)

Phoenix

Donnie: You are such a fuckass.
Elizabeth: Did you just call me a fuckass? You can go suck a fuck.
Donnie: Oh, please, tell me Elizabeth, how exactly does one suck a fuck?

Trivia: Frank tells Donnie that the world will end in 28 days, 6 hours, 42 minutes and 12 seconds. The jet engine is shown landing in Donnie's room, killing him, exactly one hour, 42 minutes and 12 seconds into the movie. (01:42:10)

Question: In the part of the movie when the science teacher and Drew Barrymore are sitting in the staff room, what does their conversation mean? Science teacher says, "Donnie Darko." and Drew Barrymore says, "I know." What significant plot does this have?