Proverbs 14:10,  The heart knoweth his own bitterness; and a stranger doth not intermeddle with his joy.

Related Verse: 1 Corinthians 2:11,  For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.

This proverb confirms the individuality of man.

It confirms the inability of man to truly sympathize with another.

It shows the weakness of the phrase, "I know how you feel."

Only the individual knows his own bitterness, only the individual knows his own joy.

No individual on earth knows your heart!

It has been written that: "Everyone is inwardly the only true and faithful judge of his own joys and sorrows, and none else can truly perceive them." and

"Each mind has an interior apartment of his own, into which none but itself and the Divinity can enter."

The sufferings or joys that we most deeply feel cannot be imparted to another, even to our mate or those friends dearest to us.

God has so made us that no two of us are alike and therefore there cannot be a complete understanding by others of our inner state.

We are truly individuals in that sense.

Each of us as individuals walks alone, we all tread a solitary path.

No one on this earth truly knows you or truly knows me.

I know your outward frame, I know your house, but I don't really know you, the real you.

Job experienced this when his friends tried to comfort him:

Job 13:4,  But ye are forgers of lies, ye are all physicians of no value.

Job 16:2,  I have heard many such things: miserable comforters are ye all.

And likewise Hannah being afflicted in:

1 Samuel 1:10-13,  And she was in bitterness of soul, and prayed unto the LORD, and wept sore. And she vowed a vow, and said, O LORD of hosts, if thou wilt indeed look on the affliction of thine handmaid, and remember me, and not forget thine handmaid, but wilt give unto thine handmaid a man child, then I will give him unto the LORD all the days of his life, and there shall no razor come upon his head. And it came to pass, as she continued praying before the LORD, that Eli marked her mouth. Now Hannah, she spake in her heart; only her lips moved, but her voice was not heard: therefore Eli thought she had been drunken.

And the Shunamite woman:

2 Kings 4:27,  And when she came to the man of God to the hill, she caught him by the feet: but Gehazi came near to thrust her away. And the man of God said, Let her alone; for her soul is vexed within her: and the LORD hath hid it from me, and hath not told me.

We have no right to judge another's state by our state.

We truly do not know how another feels.

We do not know how another reacts to a situation.

We do not have the tools to know the bitterness or the joy of another.

But thank God, we are not without comfort or understanding.

Hebrews 4:15 says,  For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin.

In Isaian 53:3, we are told that Jesus Christ is a man of sorrows, and well acquainted with grief.

When we are in Christ we cease to be an individual, alone with our own bitterness, our own grief, our own joy.

We have him fully, as if we were the only son he has.

We have his full heart, his full understanding of our grief or our bitterness or our joy.

Under his wings, into his bosom, we may pour out every heartache or every joy which no other is able to receive.

Charles Bridges in his commentary on the Proverbs says,

"Has my heart a bitterness, that thou dost not know, that thou dost not feel with me, and for which thou dost not provide a present cordial and support?"

Knowing this how can we go to the broken cisterns of man,

how can we think that we can find help in the clever inventions of the mind and the imaginations that man has conjured,

when it is absolutely impossible for man to truly know another.

Isaiah 36:6,  Lo, thou trustest in the staff of this broken reed, on Egypt; whereon if a man lean, it will go into his hand, and pierce it: so is Pharaoh king of Egypt to all that trust in him.

Jeremiah 17:5-10,  Thus saith the LORD; Cursed be the man that trusteth in man, and maketh flesh his arm, and whose heart departeth from the LORD. For he shall be like the heath in the desert, and shall not see when good cometh; but shall inhabit the parched places in the wilderness, in a salt land and not inhabited. Blessed is the man that trusteth in the LORD, and whose hope the LORD is. For he shall be as a tree planted by the waters, and that spreadeth out her roots by the river, and shall not see when heat cometh, but her leaf shall be green; and shall not be careful in the year of drought, neither shall cease from yielding fruit. The heart is deceitful above all things, and desperately wicked: who can know it? I the LORD search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.

As believers we have the living water, the flowing water, the fresh water that satisfies every need.

As Psalm 40:17, says,  But I am poor and needy; yet the Lord thinketh upon me: thou art my help and my deliverer; make no tarrying, O my God.

And: Psalm 94:17,  Unless the LORD had been my help, my soul had almost dwelt in silence.

And: Psalm 121:2,  My help cometh from the LORD, which (by the way) made heaven and earth.