Answer:
What does everyone know how to open but not how to close?
A hill full, a hole full; yet you cannot catch a bowl full. What is it?
What is eaten but not grown and was born in water but will disappear if soaked?
Tall in the morning, short at noon, gone at night. But I'll be back soon.
Everyone has it and no one can lose it, what is it?
Often cooked as fillet, this meat comes from an animal that swims underwater.