Consider this: If it was your birthday tomorrow and I gave you a gift that has most of the wrapper torn off and the gift itself having already been used, how would you feel?
"The communion of persons means existing in a mutual "for," in a relationship of mutual gift." Theology of the Body p. 61
Consider this: How can one form a bond with that gift before reconciling the fact that it has been used?
And finally, consider this: For those who have kept the gift of themselves for their one and only future spouse, it can initially be very difficult to work through the feelings of hurt, disappointment, loss, and the fact that someone else has used that gift before them. There would need to be a very conscious act of the will to forgive the one who didn't keep the gift wrapped for them before they were married.
This view of who we are, a gift, is very contrary to the messages we hear from the world around us. God made us as a gift of love! Not only that, he made us in His image! Isn't that completely amazing? What a mystery we can spend an entire lifetime pondering!
I am only now beginning to understand what it means to be a gift for my wife Lucille. And the flip side of that is I am only now beginning, after almost 3 years of marriage, to understand the mystery of her giving herself completely to me as a gift.
The "for" spoken of in the above quote can be situated like so: I live for Lucille and she lives for me. What an amazing mystery!