I’ve always found that the hardest classes depend on the teacher. For a comparison at my old school my Western Civ class had two teachers. One who you could make an A in if you put forth a minimum of effort and the other one you wouldn’t pass if you put that much effort into it.
Its also a matter of how interested you are in the subject.
To me that always is what seems to make the difference.
Undergrad: Quantum Mechanics. This is where I got off the bus with physics: when I couldn’t visualize the problem anymore, and I had to rely on the equations. When I took freshman mechanics, that was a hard course, but I could still try to think through the problems by trying to visualize the hockey puck on the frictionless plane (or whatever). But with quantum mechanics, it was a little harder to visualize a “sort of particle sort of wave, well actually sort of both, but I guess actually sort of neither, well, that’s not right either, more of, well, just do the equations and shut up.”
Grad school: I’ll second differential equations. I took the undergrad class because I’d never taken it as an undergrad and I wanted to see what the fuss was about. That class was hard. Actually I started out sitting in on a graduate level math class but ran screaming from the room.
Law School: Federal Jurisdiction. This is a tricky course for several reasons. First, federal courts are courts of “limited jurisdiction.” The federal courts are more powerful than the state courts (a federal court can issue an injunction against a state court, for example) BUT the power of the federal courts is limited–by design–because they can only hear certain kinds of cases. Much ink has been spilled arguing over just where the line is between what kind of cases the federal courts can and cannot hear, and the subject is sort of advanced civil procedure (weird, arcane procedural statutes) and advanced constitutional law (weird, arcance constitutional caselaw) rolled into one. Second, the course attracts the most competitive people in law school, most of whom want to spend their first year out of lawschool clerking for federal judges.
Mathematical Methods of Modern Physics
A cornucopiea of advanced math techniques too weird or too rarely used to justify including in normal calculus or physics classes. You know the math, where everything ceases to have any descpritive name or definition that can be applied, so it instead gets named after the nutjob that discovered it. “Euler’s Equation, Fourier Transform, Riemann Integral, etc”
I’m an architectural engineer and had to take a couple design courses. We had to do things like arrange rectangles aesthetically and according to some design principles on a sheet of paper.
That was hard.
With all the math and science stuff you know there’s a right answer out there somewhere if you just look hard enuf. But I spent more time worrying about getting those rectangles right than I ever did on my diff EQ homework…
My “Strength of Materials” class was nearly impossible. I blame the instructor since he wrote the textbook (which had to be published by the university copy center because no professional publisher would touch it.).
The classic example of a beam stuck in a wall with a weight on it? I have no idea of how to solve it.
The class instead was mostly about finite element analysis.
The hardest class that wasn’t damaged? Differential Equations - with Linear Algebra a close second.
Thermodynamics was the hardest for me – but honestly, it was more because my instructor was hopelessly obtuse and was in the habit of giving exams that did not relate at all to the homework or example problems worked :eek:
In terms of subject material, Modern Physics was a challenge because basically you learn that the reality you see isn’t really reality…and then you prove it using math! Differential Equations was rather punishing, too. I got an A- and I just found my old notes and don’t understand a thing of what I was doing.
My worst classes were intro to clinical psychology, methodolgy, economics, and intro to microbiology. Coincidentally or not, all were taught by professors who were terrible lecturers: they blathered on and on, went off on bizarre tangents, didn’t speak English well, or talked to the chalkboard or their feet. I found it difficult to even care about what was going on in those classes.
The classes I did best in and got the most out of (intro to linguistics, botany, political science, and the rest of my psychology courses) were taught by professors and TAs who were enthusiastic about what they were teaching. I suppose it was contagious, because I entered those classes with zero expectation of enjoying them.
Organic Chemistry Lab II. I get tears in my eyes just thinking about that madness!
Law School was Income Tax, all those confusing little things - our professor said awyers become lawyers so they don’t have to do math, and while I’m good at math up to a point, that code is just really tricky for me. I preferred more itneresting stuff, and taxes just seemed so dry a subject, but it was a requirement. I now have my own accountant do my taxes 
Calculus was pretty tough in college, too, but I’d rate Income Tax just a bit harder. However, while it wasn’t quite as hard because it could be on something I really liked, we had an Independent Study requirement in college (College of Wooster) taht was really exhiliirating in the way climbing Mt. Evereest would be. I wound up typing an 80 page paper with research, a couple surveys, statistics involved, etc… Now that’s hard work
Any course involving math has given me problems (with the exception of College Algebra). I struggled through financial and managerial accounting, finance, operations management, finite math, and elements of calculus. I have yet to pass statistical analysis. So, that one gets my vote for hardest class.
What’s supposed to be the hardest class for my major (management information systems) was actually pretty okay for me. I studied my ass for it, and I pulled off an A. They say that the remaining courses are a cakewalk compared to that one.
I had a hell of a time in thermodynamics. Calculus II (but not I or III) was also tough, but that may have been a combination of a bad prfessor and being new to the college experience.
Oh gawd, I forgot about Income Taxes, yes indeed that was right up there with the worst. I hope all of you have tried to read the income tax code at one time or another, it’s a fine lesson in twisted logic.
Example (fictional, but illustrates my point):
You may deduct 40% of your expense incurred in this category before 1992 unless you also filed jointly in any of the previous 5 years and did not have less than $10,000 of Schedule-A deductions in 3 of the 7 years after taking such a deduction. This limitation only applies to self-employed non-farm workers in the years prior to 1993, in 1993 the limitation was modified to include any married persons filing jointly that also qualify for the 10% credit under section 107 asset transfer rules.
ARGHHH!!!
I (broadcast journalism major) had an art history class as part of some core requirement. The class should have been called “slide memorization 101”, because that’s all the tests were. Here’s 50 slides, now write what each piece is called, who did it, what year, and what style it was. It was awful. I got a C.
And yet, I kicked ass in the “introduction to neuroscience” class I took for the hell of it.
Linguistics. My final semester of college, 9 in the morning, honors. Full of language and linguistics majors. I had not studied a language (a few years of Spanish in high school, mostly vocab) and one semester of French and one of Sign Language in college.
These were lifelong students of languages like Chinese and Arabic. They were throwing out terms having to do with declination of nouns and I don’t know what… see how much I remembered? They all already knew IPA except for my study partner who turned out to be a crystal meth addict whose dad was her dealer. This was INTRO to Linguistics. This was my last semester. I didn’t need the class, but it was fun to finally be challenged after four years of film production courses.
My final 30 page paper was a dictionary of jargon used on film sets.
Spoiler box is for the sensitive of constitution:
some are kind of dirty… so of course they’re the ones I remember…
cunt hair: a very small distance i.e: move that light a cunt hair to the right.
red cunt hair: smaller than a cunt hair
Organic chemistry, second semester. I came home from my final and literally burned my notecards in the kitchen sink, I hated that class so much. The fire alarm went off, but it was very therapeutic.
Hardest class I ever took was Biophysical Chemistry. It mercilessly kicked my butt & was the only C I ever got in college :(. Nothing in grad school even got close to that.
Well, I am a family and consumer sciences major…the hardest I have had was microeconomics. I rarely have problems in classes (I have had biology, chemistry, etc) but for some reason I could not get economics. I hated every single microsecond of it! I still have to take consumer economics.
I have to have a Textiles class that I hear is a real SOB. There are about 100 peices of fabric that you have to feel and be able to name. synthetic or real, proper uses, and proper care. Can’t wait to get that one over with!
I’m studying electrical engineering. Hardest classes so far: 1st Year Calc for engineers, 2nd Year Electronics I (Electronics II is next semester).
Just…very very tough material and I really didn’t like the profs. Especially calc…he was one of those profs who seemed to think we all had our PhDs already…uggh.
I only passed those courses thanks to the curving they had to do…
AFter Trigonal Planar’s post: Yup, I feel stupid.
Remember, is the home economist who can tell you what is a good value for your money and how to avoid scams. We are also the ones who develop the recipies you make to woo women into bed!!! Home Economists rule the world!!! 
(j/k)
Data Structures and Program Development had the highest workload. This was my introduction to serious computer science. It was specifically designed to knock out those who just weren’t able to slog through hours and hours of programming. Twenty-five hours a week was the official estimate, but I think I spent more than that. The material itself was only of moderate difficulty. The tough part was the big programming assignments and the debugging. The language was C++. Although it is my favorite, I do so hate all those seg faults, and the compiler we used was not terribly helpful with its error messages.
Signals and Systems Engineering, a required core course, had the hardest material. The class teaches how audio and video signals are encoded in various digital formats, and how various transforms and other manipulations work. I never really understood any of it. I passed just by memorizing the examples shown in class and using the exact same techniques on the exams.