You're looking at it in a Human perspective.
It is as if God gets bored listening praises over and over again.
Don't you know angels are praising God
thoughout eternity?
And if you're going to heaven, you will be praising Him
forever.
And that's non-stop! Hope you're not discouraged in going to heaven now..
Unlike human, God is not bound in time, space, including numbers.
God is not bored when he hears someone praying the thing all over again. We can read lots of repititions on the Book of Psalm.
Even Jesus, prayed the same prayers
thrice on the night of His arrest.
"..remove this cup from me; yet not what I will, but what thou wilt"
As long as you're praying from your heart, and not as a hypocrite, God definitely listens to our prayers.