wait til you get to differential equations. it's calculus with a twist, and has many applications in science/math/engineering. in high school, i actually like calculus, but by time i was at the end of my math career in college, i was sick of math. i'm so glad i don't have to take any more math courses ever! yay! but shit, all my engineering courses need math to do all the problems. oh well.
oh, btw, if you have decided on a best technique of integration you like best, you truely are a sick freak.
and integration by parts is easy. i would say of the simple techniques, trig sub is the most tricky.