A little filly

There once was a little filly, with little brown spots.
She would spend each day prancing in the field, only pausing when she reached the high fence at its southern end. She would stop before that fence, and stare up to its very top.
One day, she would jump over that fence, and prance through the strange forest beyond.
And so the days went by.
The filly would prance, and stare at the fence.
The other horses laughed at the silly filly, but she didn't give up her dream.
Instead, she grew and grew.
One day, she heard the young man who fed the herd say that the filly was going to be sold and taken to another farm.
So the filly pranced, and when she neared that fence, she quickened her pace to a gallop and leapt.
She cleared the fence.
Pausing for a moment, she looked back at the fence and the field beyond.
Then she turned, and entered the forest.