Mama T is correct below when she says that detachment boils down to a right ordering of loves.
I am thinking more about it, and detachment may also be a training in the right ordering of thoughts and of ourselves in the universe. Detachment teaches us that what is "ours" is really only lent to us as we need it. "My child" is "the child who, throught the grace of God I hold in trust for Him."
Detachment teaches us to look through the surface of things and see behind them the true wonder of the fact that they exist at all, all sustained by His gentle breath and will.
Praise God now and always in the moment and in all that we do. He is truly all that is worthy of our Love and anything we love is not truly loved unless it is loved in, and for, and through Him. Perhaps that is the lesson of detachment. I rejoice in the rose not for the rose but for the rose whispers about Him who made her. I rejoice in the moment, because He is with me and within me, sustaining me and helping me see. My joy is always in the Lord. That is detachment--I learn to love as God loves because I abandon the need to own what I love, I can let it be what it truly is in Him.
Great topic...one that near and dear to my heart.