Personally, I'd agree with SilentMartyr, though it depends on the school, I suppose. I only took 5 subjects in grade 12, which was the minimum to get into University. Physics wasn't all that hard for me, especially as the teacher rarely checked homework. Chemistry, likewise, was not that difficult, on the whole. Math 30 was probably the hardest, but I took it through correspondance, so that would account for it. Math 31 - that is calculus - was easier than 30. And English, though there were a few papers and essays, was never that hard for me. But, do keep in mind, I took Math 30 in grade 11, and had only half-days both semesters of Grade 12, so that might account for the easy feel.
Also, it might well have to do with the fact that Engineering is so much bloody harder than High School that the earlier is so much easier seeming. By fifth years its not nearly so hecktic anymore, but in first year - and second, and third - I had six courses a semester, with some four or five weekly assignments, which amounted to many hours of homework, and many late days at the University - something I was unaccustomed to in High School. I adapted really quickly, but nonetheless, I think that Engineering far overshadowed High School, in my mind. After all, it does have the reputation for being amongst the most stressful faculties.