Time for some philosophy...
I heard this saying today: "Contrast lies very closer**"
When 'X' is cutting onions, tears rolls down from her eyes. Looking at her 'Y' , has a loud laugh. Here lies the contrast. Cutting onions causes both laughter(action of happiness) as well as tears(action of sorrow).
One person's loss is another person's gain.
'A' is in love with a guy and wants to marry him.Her parents refuse the proposal and want their daughter to get married to a guy of their choice.Finally,she chooses to marry the guy of her choice.'A' is happy now, her parents are disappointed.Comfort and discomfort happens together and are closer to each other.
** courtesy: Pasupathinathan(PPN)