If you want to simplify the fly fishing cast, imagine that you are using a cheap cane pole to fish. With normal fishing you are casting a weight attached to the line, were as with fly fishing your weight is the line. When you are casting for freshwater fish, you'll be casting <30 feet while if your, salt water fishing you will be casting >30 feet (my numbers are rough please forgive me). You'll be doing the casting motion at least twice for freshwater fishing. There is an iphone app you may want to take a look at for fly casting, its a couple of bucks but its interesting.