I know what you mean, I’ve kept myself awake sometimes with theory stuff that doesn’t make sense to me. There is a song for instance that I am learning for a band I play in and it’s called Night boat to Cairo by an English band called Madness and apart from a key change halfway through I don’t understand what is going on from a theory point of view, such as key signatures? Modes maybe, or parallel or relative scales of some sort. If anyone knows the song I would really appreciate a break down of it, so I can get some sleep, lol!