Yes, I fully agree with apl. I think I need to understand more about my doubt and try to repeat it again and again clearly in my mind.

I have heard of a story of someone (maybe Larry??) that when he got a programming question, he did not ask someone else in the first but turn to his teddy bear, and he repeated his question to the teddy bear clear (and congently) times and times, and in most of time the answer will be prompted, it's more like an inpiration.