Not Just Another Recorded Poem

What kind of metaphors build up the imagery in this poem?
Why do you think this poem was titled Gypsy?

Gypsy
One day I was 15 trying to find a place to stay
running from something I never wanted so bad.

Some girls have walls you just can't break down.
You proved other girls have none at all.
And, you finally figured out how to get through each one.

But, I'm not just any girl. I stay on the move.
I can pack up my things on the notice of a transfer call
and I'll be back to get my mail later.

I had a wall that no one got through,
because there was a door
I decorated the threshold just for you.

When you knocked, I answered.
But, you didn't have a message to share
and more questions than I could answer.

You came in just for a look around and walked out.
That's why I stay on the move and make it hard for you to find me.
I don't need a father, a brother or a partner.

The next day I was 25 and I had two jobs and two degrees
and I was still running from something I never wanted so bad.