Those people we know who seem to be the happiest among us are not perfect—not even in their own happiness. No one wears a grin 24-7, after all.
Still, just as success is the byproduct of adopting the commonly shared habits of successful people and avoiding the counterproductive habits of the unsuccessful, so happiness is usually what very naturally happens when we do what happy people do and avoid the behaviors and attitudes of the unhappy.
Certainly not everything happy people do is relevant to their happiness, though. And certainly not everything unhappy people do is a contributing factor to their unhappiness. But learning the differences between the two can still be highly instructive at pointing us down the right path.