When I ponder the true meaning of joy, I turn to the Savior, for He is the Source of all joy. His atonement makes joy possible. We cannot possibly comprehend the vastness of the Atonement; nearly equally impossible to comprehend is the indvidual-ness of that same Atonement.
The Atonement is for everyone. Wonderful. But what does it mean to you, just you? Does it mean that you will never have a problem or know sadness or shed a tear? No.
What it does mean is that that the Savior is aware of every problem, every sadness, every tear you have shed and that His succor is there for you. You are known to Him, just as your children are known to you.
Joy for the day: the Atonement of Christ.