Does it not get boring chanting the same names again?
The sounds of the material world are boring, hackneyed and monotonous, but chanting is an ever-increasingly refreshing experience. Make a test yourself. Try chanting some word or phrase for even five minutes. If you chant "Coca-Cola" over and over again, even for a few minutes, it becomes practically unbearable. There's no pleasure in it. But the sound of Krsna's names is transcendental, and as one chants he wants to chant more and more.