If we adopt a self-centered approach to life, by which we attempt to use others for our own self interest, we might be able to gain temporary benefits, but in the long run we will not succeed in achieving even our personal happiness, and hope for the next life is out of the question.
If you lose your temper, your sound sleep will go, and you will have to use a tranquilizer or sleeping pills? Then gradually, more white hair, wrinkles.