Epicurus: "The cry of the flesh bids us escape from hunger, thirst, and cold; for he who is free of these and expects to remain so might vie in happiness even with Zeus."
This quote of Epicurus (341-270 BCE) is my favourite definition on happiness. Simple. Easy. It's something all of us (better: I) sometimes seem to forget.
Anyone read 'The Pursuit of Happiness' by Darrin McMahon? Why should you? Because it tells all of us that the definition on "being happy" changed a few times through history. It's only a definition, it's not a natural law of the human species.
Question: What's your definition of happiness?