To celebrate the Octave of Easter, I prayed the Glorious Mysteries today. As my mind drifted a little bit, I wondered why we have the mysteries we do. Other than the Luminous Mysteries, I confess my ignorance of the origin of the other three sets of mysteries. Then I digressed further, wondering why Bl. John Paul II didn't create further sets of mysteries. He could've gone nuts! There could be the Healing Mysteries (like the man born blind, paralytic lowered through the roof, the raising of Lazarus, the daughter of Jairus, etc.), or the Spiritual Warfare Mysteries (curing of the various demoniacs, rebuking of Peter, Gethsemane, the temptation in the desert, etc.), or the Conversion of Heart Mysteries (Saul of Tarsus, Zaccheus, Thomas on Holy Saturday, road to Emmaus, etc.). With the abundance of powerful Gospel stories, the possibilities are vast!
Yet when I came to the second Glorious Mystery, the Ascension of Jesus, I realized there was a lot more to it than just a divine elevator. I count it as an insight of the Holy Spirit: buried within the mystery of the Ascension is the great mystery of the Church. Why didn't Jesus stick around longer? We don't have any answer to that, except the Church. Because of a reason known only to God, He wanted mankind to spread the Good News. As soon as Jesus ascended, an angel appeared to the apostles and said, "What are you looking up in the sky for? Get to work." We don't know why God did it this way, only that He did.
The mystery of the Church is an awful big one to consider. There's enough in the current mysteries of the rosaries to keep you thinking, if you cast your nets into the deep.