Kyle Gann has a great vignette from his office at Bard:
Composers Joan Tower and George Tsontakis were in my office today, discussing composition with a student. George, the student's teacher, said, "We've been talking about the problem of how fast you can add contrasting new ideas to a piece without losing the listener and making the piece disunified." Joan replied, "Oh, that's a problem everyone faces." I said, "Adding new ideas? That had never occurred to me."
I'm with Kyle.