Most things are hard until you get them. But that's especially true in Maths. From elementary school to university until the necessary neurons in your head connect every problem seems daunting at first. But once you see what the actual problem is, once you see what tricks can be used they become trivial to solve.

Sometimes you just need it explained like you are five or something that was explained earlier in the "concepts" section of the textbook needs to be explained explicitly during the problem demonstration sections. And on top of that repeated explanation of the same concept is another key factor in solidifying concepts but I've found math and physics books to be so lacking in this that it's as if they are trying to hit the absolute minimum number of word count a textbook can have. Was very frustrating during college.

This is something I've been thinking about recently, I'll see something that is way too complex for me, and think "well this person is just smarter I could never do that." After 3 months of doing simpler stuff, it now seems challenging but doable, and I even see flaws in the way they did it. Just doing something for long enough, even pretty complex things become second nature.