1. One man’s constant is another man’s variable.
2. It's easier to write an incorrect program than to understand a correct one.
3. Everything should be built top-down, except the first time.
4. Each program has (at least) two purposes: the one for which it is written, and another for which it isn’t.
5. To understand a program, you must become both the machine and the program.
6. Simplicity does not precede complexity, but follows it.
7. The most important computer is the one that rages in our skulls and ever seeks that satisfactory external emulator. The standardization of real computers would be a disaster – and so it probably won't happen.
8. A program without a loop and a structured variable isn't worth writing.
9. Once you understand how to write a program get someone else to write it.
10. There are two ways to write error-free programs; only the third one works.