Mike Nelson's Mantras on Programming.
Mantra 1: Today's hot new system is tomorrow's legacy system. It will be hard to use, interface with, and support given enough time.
Mantra 2: Never call a routine 'smart', it is not. It doesn't matter how dumb the code was that it is replacing.
Mantra 3: Don't build for the future, it is unknown. Don't build for the past either for it is just as unknown. Building a new system to replace an old one is tantamount to ignoring the lessons of the past.
Mantra 4: Build for the now. Only consider what it should do today. Not what may happen tomorrow or what it could do.
Mantra 5: Mostly the tenants of maintainable code are fallacies. When he says maintainable code he just means code that he would write.
Mantra 6: All code takes effort to understand. No matter how beautiful it is. Beautiful code just makes the puzzle more interesting.
Mantra 7: No code is maintainable. Code is an object. It is only the coder that can take the action to maintain it.
Mantra 8: Is the effort to make code maintainable greater than the effort to maintain it? Why do more of a thing in order to do less of another?
Mantra 9: Do not attempt to do today what you will know how to do tomorrow.
Mantra 10: Just because you are doing work that does not mean you are adding value; you might be removing value.
Mantra 11: Just because I am using newer tools that does not mean that I am smarter.
Mantra 11: Just because I am using better tools that does not mean that I am better.
Mantra 12: A programmer is not defined by his tools.
Mantra 13: Why must I always use the latest swiss army knife when I can use the sturdy blade?
Mantra 14: Just because I write the code that does not mean I am better than the people that maintain the code. They have to deal with what I write.
Mantra 15: Just because I write the code that does not mean I am better than the users. They are the ones that I wrote it for.
Mantra 16: My software is not a gift of my benevolence.
Mantra 17: How would it help for us all use the same tools? We are not all doing the same thing.
Mantra 18: Software is never good enough. Just make sure that it is good.
Mantra 19: Do not say, "I am a C++ programmer," or "I am a Windows programmer." Don't even say, "I am a computer programmer." Instead declare, "I am a programmer."