Same here. In highschool, I really struggled with classical mechanics. A lot of things didn't click, because they were taught to us before we were taught calculus, and a lot of what I was seeing in class simply didn't make much sense. I understood the words and I could do the math, but never actually felt like I had a grip on it.

Fast forward to my freshman year and poof! mechanics suddely isn't a mess of because-i-said-so formulae that sort of make some physical sense. It's an elegant, well-thought system that can help you understand the world.

I had a further moment of revelation later on, when I seriously studied philosophy. It doesn't look like much now, but when put into their historical context, the discoveries made by Galilei and Newton are amazing leaps in human thought.