Apparently, showing yourself some compassion helps tremendously with your mental well being. From the Scientific American:
Being kind to yourself is a surefire way to improve your mental health and reach your goals, a growing body of work suggests. Now research has revealed an easy way to boost this self-compassion—by showing kindness to others.
Self-compassion is distinct from self-esteem, a trait that can shade into narcissism. Nor should it be confused with self-pity or self-indulgence. “Self-compassion is treating yourself with the same kindness and care you'd treat a friend,” says Kristin Neff, a professor of psychology at the University of Texas at Austin and the leading researcher in the growing field of self-compassion. People who are self-compassionate avoid harsh cri-tiques or negative generalizations of themselves, and they see their troubles as part of the human condition.
Research is showing that this gentle, nonjudgmental approach helps individuals bounce back even after major crises. For example, in a study in press at Psychological Science, scientists found that newly divorced people who spoke compassionately toward themselves adjusted significantly better in the following 10 months than those who spoke more harshly, with self-compassion outperforming self-esteem and even optimism as a predictor of good coping.
I've often been struck by how down people can get about themselves. The process seems to lead to a never ending cycle of self hatred, negativity and dysfunction. There's clearly a fine line between self compassion and self indulgence, but I think people should err on the side of being too nice to themselves rather than too critical. It seems pretty clear that the pressures of modern society encourage self hatred - we're constantly bombarded with images of perfection and success, and if we're not living up to it on a daily basis, it can manifest in a very negative perception of yourself. I remember telling a friend of mine who was incredibly hard on herself to take a day off from the intense self criticism she engaged in, and I think for a moment it may have provided a little relief.
Self criticism is clearly useful - the more realistic you are about yourself, the more you can improve, but there comes a point where it stops being productive and starts crushing your self belief. The people we're closest to are probably the people who accept you for who you are and vice versa. If you can show them compassion when they're feeling down about themselves, there's no reason you can't show yourself some too.