Answer:
I am the place to turn when nature calls.
I cannot be felt seen or touched. Yet I can be found in everybody. My existence is always in debate. Yet I have my own style of music.
When young I am sweet in the sun. When middle-aged I make you gay. When old I am valued more than ever.
I am in the past, never in the future. I don't exist, but have existed. I saw what you saw, and this is what I will ever see. What am I?
Use me to reward good behavior.
I tell people to be careful when handling boxes.