Answer:
People buy me to eat but never eat me. What am I?
What kind of coat can only be put on when wet?
I am needed for most animals and hardcover books
Whoever makes it tells it not. Whoever takes it knows it not. Whoever knows it wants it not
I never sleep yet sometimes I weep. I can get angry or just be happy. Wherever you go, I will follow. No matter what you do, I will be there. I cannot die. What am I?
No matter how little or how much you use me, you change me every month.