Analysis of Thief of Hearts

Aw! How my heart flies
Above the dawning skies
For it has felt a strong feeling
The most joyous sting
From something I thought I had lost
Because of a person who had one of frost
But then one of the warming sun
Has made the spell undone
I have never felt this before
And this thing I feel is only for
Something of warmth and comfort
That makes so many thoughts I cannot sort
This thing I cannot explain
Not a single tear stain
But what is thing in my heart
That resides in the most emotional part
And the person that put it there
Is this feeling something we share
For if not then what is the name of this thing
That to my heart does it cling
Or is this something true and pure
For it has its own course that I can't steer
What is this thing I feel
For my heart it will steal