Imagine we are at the center of our own little universe. An electron, let’s imagine this as a small ball, is circling around us. The path that this small ball can take is limited, it will stay in a region close to us. But where in this region the small ball can be, is not specified exactly. So while moving around us, the small ball explores this region. For example, the small ball can be at a certain point, and a revolution later, it can be somewhat more to the right. If we look at a large number of these ‘revolutions’ around us, we can try to find how many times the ball has passed a certain location. We will see that this small ball electron will have moved through a sphere around us, and will even have moved through our point in the center of our little universe! The number of times the small ball is in a certain location gives a measure on how probable it is to find the ball there. It has circled around us more than passed through our point, so it will be more probable to find the electron in the sphere around us than to find it at our center of our little universe.