Learning series and parallel circuits, and just getting a few LEDs to turn on and off is far more of a shift in thinking than you might suspect if you've never been exposed to electronics. I've been doing this stuff since I was about 10, so it came as quite a surprise to see how difficult the fundamentals were for someone who was quite adept at coding. I'd forgotten how hard it was.
Also, have you done NAND2Tetris?