Self love

Your subconscious mind does not differentiate between how you perceive yourself, and how you perceive  others. For example, your judgement which may go along the lines that "you are good" and that "the person out there is bad" is simply that "if you were to do what the other person is doing, you'd consider yourself bad." Another example of this would be if you are upset with another person your subconscious mind registers this upset as if it were "with yourself" and activates the release of appropriate poisonous chemicals into your own bloodstream. Ultimately thinking lovely and beautiful thoughts for others has nothing to do with wanting to act saintly, it has everything to do with "self-love" and taking care of yourself.