From the scientific view, the theory of karma may be a metaphysical assumption -- but it is no more so than the assumption that all of life is material and originated out of pure chance
The next time you look into the mirror, try to let go of the storyline that says you're too fat or too sallow, too ashy or too old, your eyes are too small or your nose too big; just look into the mirror and see your face. When the criticism drops away, what you will see then is just you, without judgment, and that is the first step towards transforming your experience of the world.
Keep away from people who try to belittle your ambitions. Small people always do that, but the really great make you feel that you, too, can become great.
This is the first lesson to learn: be determined not to curse anything outside, not to lay the blame upon anyone outside, but stand up, lay the blame on yourself. You will find that is always true. Get hold of yourself.