Warren Buffett's 2011-12 annual letter to shareholders, here are important quotes from it.
On value: "The logic is simple: If you are going to be a net buyer of stocks in the future, either directly with your own money or indirectly (through your ownership of a company that is repurchasing shares), you are hurt when stocks rise. You benefit when stocks swoon. Emotions, however, too often complicate the matter: Most people, including those who will be net buyers in the future, take comfort in seeing stock prices advance. These shareholders resemble a commuter who rejoices after the price of gas increases, simply because his tank contains a day's supply."
On market moves: "Here a confession is in order: In my early days I, too, rejoiced when the market rose. Then I read Chapter Eight of Ben Graham's The Intelligent Investor, the chapter dealing with how investors should view fluctuations in stock prices. Immediately the scales fell from my eyes, and low prices became my friend. Picking up that book was one of the luckiest moments in my life."