If you’re a programmer, or at least think you are, you must read this and see wether you’re starting to do things the wrong way.
Damien Katz: Signs You’re a Crappy Programmer (and don’t know it)
I really like the ending note:
Sometimes I’m crappy. Sometimes we all are. I have been guilty of most of the items on the list and still struggle with a few (especially premature optimization). So try not to take anything on the list too personally, but feel free to flame me anyway if it makes you feel better.
We all make mistakes, so the trick is trying not to make the too often. 
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