It's always reassuring to be reminded that people much more talented than myself make mistakes, too. And I especially appreciate it when they share those mistakes in the form of advice:

On avoiding IT mistakes: Rick Cattell's Things I Wish I Learned in Engineering School:

• Good technology is only 10% of "real world" success
• It's frustrating to spend years of your career building things that aren't used
• Maybe you can avoid some of my mistakes

On avoiding creative mistakes: Hugh Macleod's How to Be Creative:

1. Ignore everybody.
2. The idea doesn't have to be big. It just has to change the world.
3. Put the hours in.
4. If your biz plan depends on you suddenly being "discovered" by some big shot, your plan will probably fail.
5. You are responsible for your own experience.