From time to time, I tell people that whenever I look back at myself five years ago, I think “Boy, was that guy naive!” — and that, if I ever stop being able to do that, it’s time for me to shuffle off and never be seen again.
For example, five years ago, I was totally naive about the difficulty of implementing business-facing TDD. I was naive about how easy it would be to add exploratory testing to Agile projects. I thought that finally it would be easy to convince people of the benefits of test automation below the GUI because it fit so naturally into other Agile practices. I think my opinions about specialization were confused (and still are). Etc., etc., blah, blah, blah.
It would be good to ritualize such self-examination. A conference? Panel discussions?