I don't know who first said this, but I appreciate the quote:
"You can not lose what you have freely given."
Even after you have experienced loss, you can still decide to freely let it go, let it be as it is. Ultimately, nothing real is ever lost.
In a collection of private writings (see the book,"Come Be My Light"), Mother Teresa claimed that if you are suffering, it is because there is something you are not giving to the Divine. Perhaps if we give everything, there is truly nothing to lose.