I know where you're talking about now. I'm a good bit further than that. I haven't found any of those stand alone puzzles too hard but there's been plenty of sections where I've been standing in the middle of an area without a fcuking clue where to go next. There's at least two puzzles I've passed without even slightly understanding what I was doing!
Think I'm royally fcuked then. The odds of randomly turning knobs to get the combo seems slim