From the Ramayana
The student who would not stand for his teacher
In an earlier life Kakbhushundi was a proud, wealthy, sharp-tongued young man whose gentle teacher kept trying to guide him. One day in the temple he refused even to rise when the teacher entered. The teacher said nothing, but a curse fell on the student; the teacher at once prayed for him, asking that he not be punished in anger. Lives later, the one thorn Kakbhushundi still carries is the memory of that teacher's gentleness.
Respect those who teach you; and forgive like the teacher who prayed for his rude student.
From the Ramayana
Kumbhakarna's loyalty
Woken from months of sleep, Kumbhakarna tells Ravana bluntly that his pride caused this disaster and he acted in the wrong order. Then, loyal to his brother, he goes out to fight anyway, scorning boastful courtiers: the brave don't praise themselves, they act.
You can tell family the hard truth and still stand by them; humility does, boasting talks.
From the Mahabharata
Gautama the ungrateful
A destitute brahmin, Gautama, is fed and sheltered by a kind crane, Rajadharma, and made rich by the crane's friend. On the way home he kills his sleeping benefactor for food. Bhishma ends: there is atonement for many wrongs, none for ingratitude.
Gratitude is the root of every friendship. Betraying a benefactor poisons everything after.