God is a challenge because there is no proof of his existence and therefore the search must continue.
Donald KnuthMy first program taught me a lot about the errors that I was going to be making in the future, and also about how to find errors. That's sort of the story of my life, making errors and trying to recover from them. I try to get things correct. I probably obsess about not making too many mistakes.
Donald KnuthIn fact what I would like to see is thousands of computer scientists let loose to do whatever they want. That's what really advances the field.
Donald KnuthWhen certain concepts of TeX are introduced informally, general rules will be stated; afterwards you will find that the rules aren't strictly true. In general, the later chapters contain more reliable information than the earlier ones do. The author feels that this technique of deliberate lying will actually make it easier for you to learn the ideas. Once you understand a simple but false rule, it will not be hard to supplement that rule with its exceptions.
Donald Knuth