The heart knows its own bitterness,
and no stranger shares its joy.
- Solomon, Proverbs 14:10
Those who are bitter in heart feel it, they are very familiar with the taste and smell of their own sourness. Everyone around will notice the pungent odor of a bitter heart.
In contrast one whose heart is filled with joy delights intensely, and though strangers will miss it, his friends and family will enjoy the refreshing fragrances of joy emitting from him.