Yeah @wren486, that reminds me of the time I over-kneaded pizza dough. It got so tough I could barely stretch it, ended up with a weird, chewy crust that was almost like jerky. My friends still give me grief about "leather pizza" night.
That gluten fortress line is perfect. It's like the dough builds up too much muscle and forgets how to be soft. I've found a good windowpane test (stretching a piece thin to see light) helps avoid the whole jerky crust thing.