That question is like asking, what is the meaning of life? It has so many possible answers.
For me riding touches all of my senses.
Feel (touch) - twist the throttle, lean the bike over, shift to a higher gear
Sound (hearing) - the exhaust note, the wind rushing by, reving to redline
Taste - the sweet air in the mountains, the exhaust at idle, the bug you ate
Sight - the speedo going toward ton-up, the new engine, the wonderful outdoors
Smell - hi-test gas, burnt rubber, leather jacket and gloves
Sparty