"... it struck me as so hard to believe I was really getting what I wanted; it was always easier to feel the lack of something than the thing itself."

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I sometimes find, and I am sure you know the feeling, that I simply have too many thoughts and memories crammed into my mind. “At these times, I use the Pensieve. One simply siphons the excess thoughts from one’s mind, pours them into the basin, and examines them at one’s leisure. It becomes easier to spot patterns and links, you understand, when they are in this form.

— J. K. Rowling