Expanding your set of mental models is something experts need to work on just as much as novices. We all have our favorite mental models, the ones we naturally default to as an explanation for how or why something happened. As you grow older and develop expertise in a certain area, you tend to favor the mental models that are most familiar to you. Here’s the problem: when a certain worldview dominates your thinking, you’ll try to explain every problem you face through that worldview. This pitfall is particularly easy to slip into when you’re smart or talented in a given area. The more you master a single mental model, the more likely it becomes that this mental model will be your downfall because you’ll start applying it indiscriminately to every problem. What looks like expertise is often a limitation. As the common proverb says, “If all you have is a hammer, everything looks like a nail.”