Ernest K Gann said in his book "Fate is the Hunter"...
"We did not begin to fly because we might make more money with an airplane than we might have if otherwise employed.
We are, almost without exception, in love. It is more than love at this stage; we are bewitched, gripped solidly in a passion few other callings could generate. Unconsciously or consciously, depending upon our individual courage for acknowledgement, we are slaves to the art of flying."
This is probably the most accurate "reason" why we fly....because we ARE in love with our calling. For some of us that love might have faded a bit, but its still there. I have just under 7000 hrs and fly the "boring" line (far from the excitement of low level heli flying) but are thrilled everytime I strap this beast to my back. Every single time i start the approach, my heart beats in my throat with pure excitement and horror and love and bewilderment and enjoyment....
I LOVE THIS GAME.................!!!!!!!!!!!!!!!