Answer:
When young I am sweet in the sun. When middle-aged I make you gay. When old I am valued more than ever.
I like to twirl my body but keep my head up high. After I go in everything becomes tight
I am the book one can never finish reading
I am full of holes but still holds water.
Never ahead, ever behind, yet flying swiftly past, for a child, I last forever, for adults, I'm gone too fast.
The sun bakes them, The hand breaks them, The foot treads on them, And the mouth tastes them. What are they?