Very nice article! I really appreciate the way you described the different steps of your journey, and how you learned from them. Maybe you didn't think the same way then as you do now, but it's very positive to be able to describe our own mistakes and follow them up with lessons learned.
I was actually waiting for the answer to the title of your article (Not exactly the "answer", but I wanted to know what exactly makes a developer) and I agreed with what you said: "...it's his ability to solve problems efficiently..."
Every label we put on ourselves has to be justified. This article is a great questioning for many "developers".
Thank you!