What does something need to be described as being in a state of crunchiness? It needs crunch, right? Same thing with happiness: you need hap.
What the hell is hap?
From my gigantic The Living Webster Encyclopedic Dictionary of the English Language we get the following:
I am not really sure, though, that hap goes as far as to say unpredictable. There definitely seems to be a strong indication of participation of the individual and the environment she finds herself in. In other words, we don't simply stumble into this fortune, not only.
I defend this reading by looking for guidance from the word "happen." What does it mean for us to make something happen? It means to align our environs with fortune and delight in this alignment. "God made the world and upon observing it he was pleased," is what the KJV Bible states. Wasn't this god "hap-y?"
But note here that to make something happen is not to create out of thin air (ex nihilo) as in the case of a god that exists beyond our reality (some more Real) as the Abrahamic Traditions, Classical Philosophy, and all those relying upon Neoplatonism would suggest. To accept this teleological and inaccesibley transcendent god allows for a reasonable question like, "can God create a rock He can't lift?" He wouldn't be happy in such a cold world.
Rather, the lesson in this word happy is that we, ourselves, are the creators of the worlds in which we live and it is only in creating in a manner that maximizes the joy of our coming together (our happenings) that our sense of fate (understood here as purpose or raison d'etre) will be sated.
"But, Paul, what about the word 'happenstance,' doesn't that kinda fly in the face of your deliberativeness?"
Not at all if we allow that to be in a creative state (and thus allow for the hap-iness I am describing above) is to be enthralled by those people, places, and things that comprise our environment - to be inured and overwhelmed, in a positive sense, by life itself.
I choose overwhelm precisely because of it's root word, "whelm." What the hell does whelm mean?
From the same source above we get:
To be happy in a world that is always in flux and changing, then, is to bring close to us (to be engulfed by) that which is manifest and, with what is at-hand, make something happen. We make our lives happen when we maximize those resources our parents and surrounding communities and set out on becoming contributing members of society. And we are expected to reciprocate this gesture by having children of our own, communities of our own where those among us are also then able to make their lives happen.
This is a happy life, and it is a life that is meaning-full.