It is not something we would tend to do, if left to ourselves. There is a deeper reason, of course. It comes by means of the internal sense. But these words cannot be understood by anyone who does not know that the right cheek and the left, tunic and cloak, a mile, a loan, and all the rest are being used to mean. The subject in these verses is spiritual life or the life of faith, not natural life, which is the life of the world.
Spiritual life is the key.
This is what comes out by means of the internal sense. This again is the law of retaliation. The truth contained within is that one is the law of heaven, while the other is the law of hell. But devils in hell place themselves first, desiring to abuse and manipulate those around them. When it doesn't work they break forth with acts of violence and cruelty.