My goal is to become a master web developer.

Back in college, I taught myself how to build static websites, and then Wordpress hit the scene. I eventually taught myself how to create Wordpress themes too.

Here's my conundrum: I've recently made a commitment to become a master web developer after being away for the Industry for 4 years. I learned how to develop from watching tutorials and what not, but I want not just know the HOW of web development, but the WHY as well.

I'm aware this industry is always changing as new innovations in technology hit the market.

I need a crash course to beef up my web development skills, specifically what do I need to focus on learning to bring myself up to speed on current web development standards and principles?