Hard question. I think I’ll settle for just trying to answer a tiny little part of it:
I see two possibilities here. Firstly that the puzzles are incorrectly categorised. That’s particularly possible if they are aimed at someone who has grown up playing Go with grandparents from the age of three. Some of us were just born in the wrong country. The second possibility is that you need to focus more on learning general principles. If you don’t know the difference between a real eye and a false eye, you will still be able to brute-force your way through many simple puzzles but understanding the principle gives your thinking a shortcut.
ps. I don’t think Janice Kim’s books are very good and I’m 99% self/book taught. See: