The Glorious Mysteries represent a conclusion, and signify a new beginning. The start of a new chapter in the story of the salvation of mankind, and the epic of our life in God.
Reflecting on the Luminous Mysteries, we see a great deal of tenderness, and "humanness" in the life of Jesus and his relationships and experiences with his apostles and His Blessed Mother.
We see the suffering of the Church (the people, and the ecclesial Church) in each of the five sorrowful mysteries.
In meditating on the Joyful Mysteries, we explore the mystery of joy itself. Joy is supernatural. It supersedes the emotions, but collaborates with our emotional sense. Joy sometimes comes with sadness, it doesn't always come with happiness. But as we grow in holiness, we learn to prefer joy over happiness.