Inspired by the "most useless course you've ever done" thread, here is its evil cousin, the hardest course you've ever done.

For me, far and away the hardest thing is the 2nd year of my Chemistry Degree, 3 term, Physical Chemistry subject, Statistical Mechanics

1st term P.Chem was Thermodynamics, and I was pretty good at that, with a bit of effort I did OK. 2nd term was Nuclear Chemistry/Quantum Mechanics, far and away my best subject in my entire university education, it almost came naturally.

Final term they combined the two together to create Statistical Mechanics and it was hard with a capital H.A.R.D.

1 hour, 3 times a week, for 10 weeks I just sat there with my brain throbbing trying to take it in, barely understanding a word that was being said Everyone struggled in that class, even the geekazoid no-life-outside-of-campus-90-percent-is-a-low-score-types. I felt like Homer Simpson at the end of every lecture

I managed to drag my sorry ass through the course and scrape a pass. My final year was a doddle after that