The symbol for Taoism is the classic yin/yang, with a bit of one in each. Without long you wouldn't know short, without dark you wouldn't know light.
Life does happen in shades of comparison, but you can also compare how much better you feel compared with how good you already thought you felt!
Another way I like to think about it is a story I read in 'Zen And The Martial Arts'.
A line was drawn in the sand, and the author was asked how he'd make the line shorter, without touching it.
He puzzled over it for a while, and gave up.
A longer line was drawn next to the first one.
