Warren Buffett's annual letter to the shareholders of Berkshire Hathaway was not only about reflecting on the past year but also on the past 58 years of his career. In it, Buffett proposed that his success is due to "about a dozen truly good decisions", or roughly one every five years. His theory of success is about getting important decisions phenomenally right, not getting every decision right. Buffett advised investors to imagine they are holding a punch card with 20 slots for the total number of investments they can make over their lifetimes. Fewer than 20 decisions made the difference for him, with some of his most valuable investments including buying Coca-Cola and American Express dividend stocks, finding a partner like Charlie Munger, and investing in See's Candies.