Here's the best quote about a principles course that I've seen in a while. The Harvard Crimson reviews Greg Mankiw's Ec 10 course.
...it teaches concepts that will seem so intuitive you’ll be embarrassed by how little you knew before taking the course.
Hat tip to Greg Mankiw, of course.
I don't know about Mankiw's course, but I pulled out my old Principles book from graduate school and reread the section on cyclical vs. structural budget deficits.
I guess my book is out of date since Mankiw apparently teaches that structural deficits, like the current Bush structural deficit, "don't matter". On well, I'm so old fashioned!
Best Wishes.