Answer:
He has one and a person has two. A citizen has three. And a human being has four. A personality has five. And an inhabitant of earth has six.
I go around in circles, but always straight ahead. Never complain, no matter where I am led.
This only turns over once you have travelled very far. What is it?
Long and slinky like a trout, never sings till it's guts come out.
Iron on a mammal. Mammal on your feet.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.