I totally see where your coming from, and no its not jusr you!. Your probs quite clever anyway, but I do agree that teachers tend to way over complicate things!!! Like I always find myself completely lost during the year, and then when i bother to pick up a book before exams, I realise that actually its really not that bad!! I feel like teachers just have to fill up time, coz come on, it doesnt take a whole year to go through 1 textbook (refering to sciences etc), so they probs have to add in other irrelevant stuff that just confuses people...at least my teachers do!
And I think self teaching probs also helps...coz many people just rely on teachers/ tutors, and never actually bother themselves. The best way to learn is deff by sitting and struggling until youve made sense of the material for yourself!
Although, I wouldnt say the exams are easy...i mean many people dont do well. But if your decently clever, and put in the effort, then ye, youll do well!