Answer:
I travel in a gaggle.
I cannot be bought, cannot be sold, even if I'm sometimes made of gold. What am I?
I am bought by the yard but worn by the foot. What am I?
I am taken from a mine and shut in a wooden case from which I am never released. Yet I am used by almost everybody. What am I?
I soar without wings I see without eyes. I've traveled the universe to and fro. I've conquered the world yet I've never been anywhere but home.
What made Cyclops quit teaching?