What we commonly refer to as Search Engine Optimisation is something which I relate to treatment of a disease. The various treatments of SEO, from title tags and headers to information architecture and linkbuilding, are all focused on the symptoms of a disease.
Truly understanding the disease – i.e. going beyond the symptoms and superficial treatment – requires a deeper understanding of SEO. It requires that you understand how search engines work.
This aspect of SEO is, in the opinion of many including me, thoroughly neglected in our industry. Too many search engine optimisers focus exclusively on the symptoms and are entirely oblivious to the underlying causes.
Understanding how search engines work and how search engineers at these search engines tackle problems is a vital aspect of becoming a truly well-rounded SEO specialist.