S: Why do people cry?
M: What do you mean?
S: I mean, what happens physically?
M: Well... umm... tear ducts operate on a normal basis to lubricate and protect the eye and when you have an emotion they overact and create tears.
S: Why? Why do they overact?
M: [pause] I don't know.
S: Maybe... maybe emotion becomes so intense your body just can't contain it. Your mind and your feelings become too powerful, and your body weeps.
(Filmzitat - Stadt der Engel)