The heart knows its own bitterness, and no stranger shares its joy.
This agrees with Co1 2:11, What man knows the things of a man, and the changes of his temper, save the spirit of a man? 1. Every man feels most from his own burden, especially that which is a burden upon the spirits, for that is commonly concealed and the sufferer keeps it to himself.
The heart knoweth his own bitterness,.... Or "the bitterness of his soul" (l), the distress of his conscience, the anguish of his mind; the heart of man only knows the whole of it; something of it may be known to others by his looks, his words, and gestures, but not all of it; see Co1 2:10; bitterness of soul often arises from outward troubles, pains...
Each one best knows his own sorrows or joys.