My illusions about the world caused me to think that in order to benefit by my reading I ought to possess all the knowledge the book presupposed. I was very far indeed from imagining that often the author did not possess it himself, but had extracted it from other books, as and when he needed it. This foolish conviction forced me to stop every moment, and to rush incessantly from one book to another; sometimes before coming to the tenth page of the one I was trying to read I should, by this extravagant method, have had to run through whole libraries. Nevertheless I stuck to it so persistently that I wasted infinite time, and my head became so confused that I could hardly see or take in anything.