When you ride as opposed to drive, you experience the ride with more of your senses than when you drive. The smell of the air, the sound of the road and everything else, the vastly increased view of your surroundings, the feel of the machine, and even the taste of the bugs (
).
You are also controlling the machine much more actively, and getting much more feedback from it. That is also why I chose the S40, as opposed to a larger, heavier bike.
My brother-in-law has raced just about everything with a motor, and his favorite is flat track. He says it's because you have a more intimate sense of being one with the machine than you do anywhere else.
The only thing I can think of that I have done that is more of a total experience is sailing.