One of the first comments made by the author was that he had the bad habit of writing div soups, and after his refresher not only was the author aware of a respectable list of semantic HTML elements and their appropriate usecases but he also was made aware of the importance of using HTML right to handle accessibility.
Sounds to me that it made two profound improvements over the author's HTML abilities.
On the other hand it is admirable that OP turned towards his own ignorance with an attitude of acceptance for the sake of improving his own knowledge. Too many people assume their own expertise and don't return to the fundamentals often enough.
As someone who also created hobby websites with FrontPage/Dreamweaver/whatever code editor I could find years ago during my schooling days, it was nice reading the tl;dr of how HTML has evolved, and what some of the best practices are now.
Sounds to me that it made two profound improvements over the author's HTML abilities.