Too Long; Didn't Read
You've heard that keywords are important to your SEO rankings. This is true to a large degree but probably not in the way you expect.
Keywords matter and they should be used to help you create content that matches your reader's intent.
However, you should not be using them as a way to fill your blog posts and articles with fluff.
In fact, keywords aren't the be-all and end-all of SEO.
The truth is that Google's algorithm uses a lot of different factors (as many as 200 factors) to determine where you rank for different search terms.