Electrons move in mysterious ways; the Heisenberg principle states that we can never simultaneously know the location and velocity of such small particles. But when an electron is bound to an atom within a molecule, it's effectively confined to a particular area, the shape of which is a probability distribution cloud. At every point within the cloud, there exists a probability that the electron will be located at that point. This cloud is also known as an orbital.
I just figured this behavior is kindof like mine - I am subject to flights of fancy and start too many projects, all within a defined but broad scope of interest, and if you try to pin me down, my nature is to get distracted and end up working on some other project for a short while, and then something else, and so on. But I do revisit most of them from time to time.