Answer:
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
I'm light as a feather, yet the strongest man can't hold me for more than 5 minutes.
Thirty white horses on a red hill, first they champ, then they stamp, then they stand still.
I have a tongue, but do not talk. I follow close, but neither run nor walk. Coupled and hitched, but never married. You couldn't bear the load I've carried.
Round as a button, deep as a well. If you want me to talk, you must first pull my tail.
I have two eyes in the front and a lot of eyes on my tail