Am I not experienced enough to learn Wordpress development?

Having spent some time learning HTML and CSS on the web design track, I switched to the Wordpress development track, partly to have a break from all that coding! However, although I can follow along with the basic ideas and concepts, I'm not really understanding how the PHP works, and I'm concerned that I'm progressing through the course without a real understanding of how and why things are working. I certainly don't feel I could reproduce much of it on my own, which is slightly disheartening, and not at all how I felt about the CSS course.

I couldn't see any prerequisites for the WP dev course apart from a basic understanding of how WP works. However, I've now come across a comment from Zac in another thread (https://teamtreehouse.com/forum/good-idea-to-learn-wordprees) where he advises:

"If you want to learn to learn a variety of languages and programming platforms then yes, learning PHP and WordPress is a good idea. Knowing HTML, CSS, JS and PHP are all preqs for our WP Dev courses tho, so make sure you learn those first."

I'm therefore wondering if I'd be better off going away and learning those languages and coming back to WP when I've done so. If anyone has any thoughts on this, or is willing to share their experiences with learning WP development as a newbie to programming I'd be really grateful.