This clip may not look like it has anything to do with persistence, but trust me, the film does. Not only does it use the analogy of running to discuss how one copes with those moments--in running, in love and, I'd add, in writing--when one hits the wall, but there's a great scene in which the main character, Dennis, tells his son the following:
Dennis: As you get older, you're going to realize there are a lot of things that you don't like, OK? Things much worse than this. And when those things happen you can't just run away.If that doesn't sum up writer's block, I don't know what does. It also sums up the problem of not having enough work, or not enough higher paying work or not enough of the work you really love. Persistence isn't just about solving the problem in front of you now, it's about developing a means to solve every problem you face. It's about creating a system that makes problems solvable, even if the system is just to take a break and keep coming back to it enough times that the problem cracks.
Son: Why not?
Dennis: Because it doesn't solve the problem. When you stop running, the problem's still there. You've got to stick at it and then figure out some way to solve the problem. Even if it's really, really hard.
And rent the movie, because it's hilarious.