Answer:
When young, I am sweet in the sun. When middle-aged, I make you gay. When old, I am valued more than ever.
What type of paper can you neither read nor write on?
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain. Doing no harm, and feeling no pain.
Some try to hide, some try to cheat. But time will show, we always will meet. Try as you might, to guess my name. I promise you'll know, when you I do claim.
What never gets any wetter no matter how hard it rains?