I learned SEO in a project that went so good that I made a business out of it. Living in Greece at the time it was logical to make something new in the travel business, so I created a travel guide about Greece and the Greek Islands. As I am also a front-end developer I learned quickly the semantics and had good use of the experience to implement SEO and hierarchy of information value.
Since then I have helped companies to understand their meaning of having a website and a digital platform. Or why they should loose is and do something else 