SEO is as complicated or as simple as you want it to be.
Search Engines are designed to do exactly what they’re supposed to do; they find the stuff you’re looking for and put it in front of your face. And they do this through the use of words and key-terms.
Experts in SEO will of course always deliver crazy-good results that the layman wouldn’t ever be able to get a hold of themselves, but that doesn’t mean the average person with fingers, a keyboard, and an idea in their head can’t get pretty darn good at SEO just naturally.
It takes a bit of consideration on how SEO works fundamentally to write out really good content and make your site in such a way that fits what other people are going to be searching for. This also depends greatly on the search engine that you’re optimizing for. For example, Russia has its own primary search engine that has different rules.
Mostly though, just keep key words in mind and write content that will engage the people that you expect to go to your website. Essentially, think of a search engine as a guy who has been to every corner of the internet and will recommend things to people depending on what they say they’re looking for.
As long as you keep that in mind, you should be able to write okay-content for your blog or independent website, and you should get decent search engine results.