Well, I had old exams online and solutions, I worked maybe 1/5-1/4 of the problems on about 1/4 the exams and got them right, exactly. I only did the ones that looked doable. They included game theory, logic, and optimization problems. Problems asking about abstract algebra, real analysis, topology and other math-intensive subjects were nearly indecipherable to me. That being said, I am still doing better on these tests than the best math majors at my school, which is what irks me. I don't think the problems I solve are hard problems. Then again, most solvable problems aren't hard.
And I agree that how the subject is taught has a lot to do with how hard it ends up being. But that's true of any subject; anything can be taught in such a way that it's arbitrarily hard. IMO, that is.