The physics of surfing is way more specific than you think.
Also, I had to discuss the push forward thing myself. Every surf instructor in the world will tell you to work on your push-ups. But nobody bothers to tell you that you not only have to push yourself upward, but push forward with your hands. Get yourself in a downward facing dog position. The key is to get your hips high so you can fit your legs under you.
Your hands must line up with your center of gravity. This was an extra huge challenge for me because of my extra huge ass. Surf instructors on the internet are generally dudes with no asses, so their advice wasn't the most helpful.
Now, I'm out here constantly practicing my muscle memory so I can keep getting my feet under me.
Maybe one day I'll write a proper surf instructional book.