I like to avoid fads. I think it's the rebel in me. I have never read a Left Behind book, for instance.
And I am not a Harry Potter fan. I have not read any of the books, and I tried to watch the first movie but fell asleep - twice.
I did, however, find it very interesting to hear on NPR tonight while I was driving home that JK Rowling wrote the final chapter to the seventh and last Harry Potter book back in 1990, before the first book had even been accepted by a publisher.
Beginning with the end in mind is one of Stephen Covey's 7 Habits of Highly Effective People (a fad I did get into). Any way you slice it, JK Rowlings has been highly effective and successful.