Being on a bike and in a car is very different.
Of course, I'm not talking about the obvious differences like a bike is two wheeled and a car is four, a car has a roof over your head and doors to open but a bike doesn't (duh~).
What I'm talking about is the whole feel, the sensation, the mood and the intensity of adrenaline.
I'm sure driving a super car gets your adrenaline pumping with staggering fast speeds (0 - 100km/h in 3.7 seconds for the Ferrari 599 GTB Fiorano), especially at the revving sound of a 500bhp engine ready to pounce each time you shift the gears. But no matter what, you're sitting in the car and comfortably surrounded by the plush interior of the vehicle.
Whereas on a motorbike, you are.. free, and your senses come alive.
It's your body which encompasses the entire machine, the sound of the engine that are music to your ears, with the winds gliding on your skin, while you throttle from 0 - 150km/h in seconds as you feel this overwhelming sense of power that unleashes something called freedom from within, that translates into a different form of adrenaline that drivers cannot comprehend.
Watch "Why We Ride" by Walking West Entertainment Gnarly Entertainment, directed by Byan H. Carroll that accurately delineate the freedom of riding.
It will give you goosebumps ;)