Men do not speak of it to others, still less to those whose neglect or coldness inflicts it; yet It is like thorns in the pillow.
"Blow, blow, thou winter wind; Thou art not so unkind As man's ingratitude." Parents suffer unspeakably when the children for whom they have lived, suffered, and sacrificed, prove ungrateful.

The ungrateful child does not know what bitter sorrow he causes the mother who bore him and nursed him, and the father who loves him more than his own life; how their hearts bleed; how they weep in secret over his unkindness.

We do not know how we hurt our friends when we treat them ungratefully, forgetting all they have done for us, and repaying their favors with coldness.
There is yet more of this lesson.

Gratitude, to fulfil its gentle ministry, must find some fitting expression.

It is not enough that it be cherished in the heart.