Answer:
Six letters do my name compound; among the aged oft I'm found; The shepherd also by the brook hears me when Leaning on his crook; but in the middle me divide and take the half on either side each backward read a liquor tell ev'ry gay toper knows it well.
You see a boat filled with people. It has not sunk but when you look again you don't see a single person on the boat. Why?
I have no voice but I can teach you all there is to know. I have spines and hinges but I am not a door. Once I've told you all, I cannot tell you more. What am I?
I can be repeated but rarely in the same way. I can't be changed but can be rewritten. I can be passed down but should not be forgotten.
I reach for the sky but clutch to the ground. Sometimes I leave but I am always around.
Often cooked as fillet, this meat comes from an animal that swims underwater.