What's the fun in being predictable? Are you unpredictable is the question.. Complicated and inconsistent responses to situations makes you unpredictable. There is another way - not letting others know you in detail. Brain has evolved to an unfathomable extent that it complicates the responses to situations intentionally making people mysterious about the ways you respond. That kind of responses are being called matured responses by the society. Keeping it simple is not fun it seems. You have to have atleast one more face above your face.
I could rationalize unpredictable responses only as a survival instinct. But brain gets habituated in responding that way even when something doesn't jeopardize its survival. Isn't that hypocritical? People's responses at situations like that are callous. If everyone can live without emotions, it wouldn't matter. Lot of Jokers(played by Heath Ledger,as in The Dark Knight) are required to make people realize what they really are!
People,Hypocrisy is ugly!