When it's over, I want to say: all my life I was a bride married to amazement.
When her life is over, our speaker wants to know that she lived her life amazement by everything around her.
She compares the ideal bond to a marriage.
Marriage suggests both intimacy and a life-long commitment.
Also, there's a sense of staying in that moment of the wedding. She doesn't say she wants to be a wife, but a bride. So it's like it's the wedding day every day. She wants it to be constantly new, wants every day to be a renewal of the vows, of her amazement at the world.
I was the bridegroom, taking the world into my arms.
She wants to know that she embraced the world.
She's flipped the marriage arrangement: this time she compares herself to the bridegroom, and the world to the bride.
This has a way of making the relationship seem both fuller and more equal.
And again, it's like a perpetual wedding day. Each day our speaker wants to take the world into her arms – which involves reaching out to and embracing, creating a unity, and actively bringing herself and the world together.