Is time a line or a circle?

I was never too good at history,
But this fable I well knew,
How the war between two countries,
Became the Taming of the Shrew

But did you ever see the end of that?
It was one of Shakespeare's comedies.
He also wrote Romeo and Juliet
The an heroes of teen angst - tragedies.

I said I was bad at history
Those who don't know it are doomed to repeat it,
I guess I didn't know that story so well.
Or maybe history can never be defeated.

Maybe this wont end like the battle,
In all the hate and the cold
Now salt is being sold to snails,
But the tears grow old

I know I am bad at history
Maybe I really can't foretell,
They say hindsight is 20/20
Too bad I'm too blind to see what I should know so well.