There are a number of ways the repetition in this and other prayers help me personally, so I'll tell you about those. First of all, they serve to change my heart. St Paul said in Romans 12:2: "Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is--his good, pleasing and perfect will." One of the ways we can transform our mind for the bad is to repeat bad thoughts over and over. For example, saying "I'm so dumb." If you say something often enough, you'll start to believe it. We can do the same thing with good thoughts. I remember when I first heard the Chaplet of Divine Mercy, praying , "Have mercy on us AND ON THE WHOLE WORLD," I thought that was an impossibly big ask -- the WHOLE WORLD?? But as I prayed that sentence 50 times every time I prayed the chaplet, my heart began to change, and while I still know it's a big ask, I truly believe it when I'm praying it! Let me just say, though, that you need to pay attention to what you're praying ... not just repeat it meaninglessly. I did something similar when I needed to transform my mind to believe about myself the things that God says about me in Scripture -- I'll try to remember to do a video on that soon, as it's helped many people. The repetition can also help us to pray. When praying the rosary or the chaplet, I like to think of, or say the name of a different person on each bead and pray that prayer for them. It doesn't allow me time to pray a lot of things for that person, just what's in the prayer: And that's something I know God wants for them! We can also use the repetition as a backdrop in which to meditate on some of the mysteries of the Gospel -- that's what we traditionally do with the Rosary. The repetition can make prayers like the Chaplet or the Rosary difficult. We can find our minds drifting and we can fall into meaningless repetition -- which Jesus warns about. When this happens, ask God to forgive you and move ahead. I think of it as the challenge Jesus gave to His disciples in the Garden: He asked them to watch (fast from sleep) and pray while He was in agony. When I accept the challenge of the repetition of these prayers, I feel like I'm kind of doing that.