If we have the case of an infinite potential well, the particle is assumed to have 0 potential energy when inside the well at all times. Why is that? Does it assume that the box itself is 0 net charge? This is because any non zero net charge and the electron will either be repelled or attracted meaning positive potential energy for some time. Or does it imply either infinite negative or positive charge on both sides? If that is the case than why is it still 0 potential evergy at all points inside the well?