Saint John Paul II in Rosarium Virginis Marie wrote:
Meditation on the mysteries of Christ is proposed in the Rosary by means of a method designed to assist in their assimilation. It is a method based on repetition. This applies above all to the Hail Mary, repeated ten times in each mystery. If this repetition is considered superficially, there could be a temptation to see the Rosary as a dry and boring exercise. It is quite another thing, however, when the Rosary is thought of as an outpouring of that love which tirelessly returns to the person loved with expressions similar in their content but ever fresh in terms of the feeling pervading them.
In Christ, God has truly assumed a “heart of flesh”. Not only does God have a divine heart, rich in mercy and in forgiveness, but also a human heart, capable of all the stirrings of affection. If we needed evidence for this from the Gospel, we could easily find it in the touching dialogue between Christ and Peter after the Resurrection: “Simon, son of John, do you love me?” Three times this question is put to Peter, and three times he gives the reply: “Lord, you know that I love you” (cf. Jn 21:15-17). Over and above the specific meaning of this passage, so important for Peter’s mission, none can fail to recognize the beauty of this triple repetition, in which the insistent request and the corresponding reply are expressed in terms familiar from the universal experience of human love. To understand the Rosary, one has to enter into the psychological dynamic proper to love.
One thing is clear: although the repeated Hail Mary is addressed directly to Mary, it is to Jesus that the act of love is ultimately directed, with her and through her. The repetition is nourished by the desire to be conformed ever more completely to Christ, the true programme of the Christian life. Saint Paul expressed this project with words of fire: “For me to live is Christ and to die is gain” (Phil 1:21). And again: “It is no longer I that live, but Christ lives in me” (Gal 2:20). The Rosary helps us to be conformed ever more closely to Christ until we attain true holiness.
Rosarium Virginis Mariae 26