Happiness, what a word ha! I've heard and red hundreds of definitions of this word, this feeling, but the best one and the most reasonable one is this my friend: it say's that Happiness is where there's balance between these most important sides in a person's life: SPIRIT, HEALTH, PROFESSION & SOCIAL LIFE, so, any lack in any of these four, will cause you a feeling of unhappiness, it means that even if you're perfect in three of those categories, and you lack in the fourth, you'll be unbalanced somehow...
But there's something you must know, and you'll admit it sooner or later, the most important side of those four is the SPIRITUAL side, because even if you're ill (health), broke (profession) and unsocial or hated by people (social), but you live in peace with youreslf and HEART, and your conscience is comfortable, believe me, then you're the happiest and luckiest person on Earth...
It's the glaobal materialism that made us like this, not knowing what we're doing here, in this life...
I wish you all a happy life ^_^