Answer:
Passed from father to son and shared between brothers, its importance is unquestioned though it is used more by others.
We traveled the sea far and wide. At one time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly. How can that be possible?
What is filled with air and sometimes a gas, tied to a string and often seen on your birthday?
What is used by man, tossed by trees, everywhere but unseen?
What is something you can give away as many times you want without ever losing it?
I fly to any foreign parts assisted by my spreading wings. My body holds an hundred hearts Nay I will tell you stranger things when I am not in haste I ride and then I mend my pace anon.