Why does one write?

What fickle emotion caused an individual to pour their thoughts into this fickle little beach we call reality?

Is it joy?
Such a blooming emotion that sends gentle waves that lap upon the shore,
Changing the way it looks over time,
Until one day it is unrecognizable lest you squint your eyes really hard,
and turn your head just-so.

Is it love?
That soaring thing that can bring new perspective to a shore that you have seemingly memorized through years of meandering along it's lengths,
Making everything bright and new again.

Is it anger?
A maelstrom that drives into the shore with an almost unatural fervor,
Furrowing and scarring the shoreline in a single night,
But it's effect lingers for many years to come.

Is it nostalgia?
That message in a bottle that you always seem to stumble into while exploring the shore's short length,
Only to realize that the messages have arrived always just a bit too late,
Not enough to cause a noticable impact upon the beach to an outsider,
But brings new meaning to the person who finds it.