Here is a great article about some advice given to a 22 year old starting his life journey. These points are applicable to anyone, but found them especially applicable to software developers in general.
http://www.tawheedkader.com/2010/11/what-not-to-do-in-life/
Here are a few that I particularly enjoyed
Do not ever work
Picasso used to paint all the time, Henry Moore sculpt the whole day. Others would have thought they were working themselves to death. They actually were reenergizing and reinvigorating themselves. Do what you enjoy doing. Do not ever work.
Do not go into any competition
Quality has no competition. Only mediocrity has competition. If you do what you do at the highest quality you have no competition. Quality creates a moat around yourself.
What this says to me is “Love what you are doing, and don’t make crap!”. These are super wise points that we often overlook. Take for example the iTunes App Store. 300,000 apps where ~ 290,000 of them are total crap. People just writing apps for the sake of making money and not truly enjoying what they are doing.
If you are competing on crap, you are always going to lose.