In order to refine the idea, the viewpoint of others is important. For example, when you look at a sphere from a certain point of view, more than half of the sphere is not visible.
When the visible range is a smooth spherical surface, it tends to be assumed that the unseen place is also a smooth sphere. But it may be sharp and holes may be open. It is impossible to observe from your point of view.
The more you succeed at the current point of view, the easier it is to forget about things that you do not see. In order not to overlook the back side of the sphere, it is important to observe from different perspectives. Even when you see things by yourself, it is important to strive to see from multiple perspectives, but it is not easy. You can achieve it more easily by borrowing the eyes of others.
