I hear that calc II is the hardest course in the calculus sequence. I am not sure why this is, but it is something that I hear constantly. Why is it considered to be so difficult? Are there a lot of formulas or are there many different applications of formulas, ideas, and logic? Obviously people will have different experiences with calc II, but I am really interested in hearing any opinion as to why this course is hard, easy, or of an average difficulty.