Is It So Critical to Have Variety?

In your book, you talk about predictable rewards and how they fail to fully stimulate our brain's circuitry. Why is it so critical to have variety? A meser, i's critical for all of us. I think it's critical for some of us. But we're expressing it in very unhealthy ways, like we do a lot of our programmig these days. It's good that we have it, but it's also good to recognize and understand it,.