We don't like it when we lose something. We think, "What gain could there be in loss?" But loss, too, is a way of growth.
Much of growth is simply learning to let go, to loosen the cord that ties you to your "stuff" -- to your material things. Such as this thing you are missing.
Only once that is achieved can you emerge onto a higher plane, a plane open wide enough to contain more light and life than before. The divine energy that before brought a loss, can now bring -- openly and clearly -- a blessing and much gain.