Curiosity is good as a triggering point for a quest, but there are many people who simply remain curious their whole life. Their life is a wastage; they are rolling stones - they never gather any moss.
They remain childish, they never become mature. They ask a thousand and one questions, but they are not really interested in answers. By the time you have answered them, they have prepared another question. In fact, when the Master is answering the question, if the disciple is only a curious one, he is already thinking about other questions to ask. He is not listening to the answer at all. He is not interested in the answer, he has enjoyed asking the question.
And then your curiosity can get you hooked on something utterly nonsensical. There are people who are curious as to who made the world. Now this is utter nonsense. Buddha said it so many times, that "How is it going to affect your life? It is not going to deepen your meditation, it is not going to help you become enlightened, it is not going to give you freedom, it is not going to give you any light; why are you concerned with who made the world?" Whether it was A or B or C, a Christian God, a Hindu God or a Mohammedan God, how does it matter to you? Even if it is decidedly known that A made the world, what are you going to do then? Then you will start asking something else; that question is finished.
But these questions are never finished, because these questions are utterly meaningless, absurd - so they are never finished. One can go on asking and asking and asking, and the whole life can become just a wastage.
-Rajneesh