When it becomes necessary to develop a new perception of things, a new internal model of reality, the problem is never to get new ideas in, the problem is to get the old ideas out. Every mind is full of old furniture. It’s familiar. It’s comfortable. We hate to throw it out. The old maxim, so often applied to the physical world, “Nature abhors a vacuum” is much more applicable to the mental world. Clear any room in your mind of old perspectives and new perceptions will rush in. Yet there is nothing we fear more.