A new study reveals that most movie quotes follow a certain set of criteria:
[M]emorable phrases tend to use very ordinary grammatical structures that are highly likely to turn up in the corpus. They also found that memorable phrases tend to use pronouns (other than you), the indefinite article a rather than the definite article the, and verbs in the past rather than present tense. These are all features that tend to make phrases general rather than specific. So memorable phrases contain generic pearls of wisdom expressed with unusual combinations of words in ordinary sentences.
Test the formula for yourself here.