In the West, people see the ancient Chinese Yin Yang symbol and think that it represents stark contrasts--good vs. evil, etc. In reality, the two shades in this powerful symbol are not intended to be contrasting opposites. Rather, they are complimentary pieces of the whole.
Life is light and life is dark. When we embrace the shady as well as the sunny side of living, we find ourselves less attached to things being a certain way. And, as a result, we are happier.