I started my IT career as a systems administrator, moved into building websites and colocating servers of my own. I started a small hosting company and domain registration services in 1997 and have worked with search engines since. I Was a DMOZ editor and have seen every trick in the book trying to manipulate search engines.
I have had great success with not too many colossal failures. Luckily, I have been able to learn from mistakes I have seen from others and myself then turn them into insight. Some of us just seem to understand what works and what does not. I believe I am one of these people with the natural ability to understand this very small corner of the Internet. I have no formal training in this area as I was around when SEO was born.