Hardest school subect you''ve ever studied?

Spanish, because I'm not interested in learning it. I was forced to take 3 and a half years of it. 1/2 a year of Exploratory, 1 year as an introduction, Spanish 1 and Spanish 2. I'd rather learn something more interesting, like Japanese or Italian. =]

Edit: I equally hate Bio. But last year my teacher made the class interesting, he just told stories almost the whole hour and a half block. I passed my Bio NYS Regents with a 78, not bad. =P