Step-by-step explanation:
Lord Rama asked his brother Lakshman to go to Ravana and learn something about the world. Lakshman obeyed his brother’s order and stood near dying Ravan’s head. But Ravan did not say anything and Lakshman returned to Rama. Rama then told Lakshman that whenever one wants to learn something from a person, you should never stand near his head, but his feet.
Lakshman again went to Ravana and this time he stood near his feet. Ravan aseeing Lakshman standing near his feet told him Three main secrets that would make anyone’s life successful.
1 - The first thing Ravan told Lakshman was that one should complete any auspicious work as soon as possible and keep delaying the inauspicious work as much possible.
He told Lakshman that he could not recognize Rama and therefore delayed arrival at the shelter. Hence this is his condition.
2 - The second thing he taught Lakshman was never to underestimate one’s enemy. He said that he did this mistake of understanding the monkeys and bears lesser or incompetent and he lost the battle against them.
He said, when he asked Lord Brahma to make him immortal, he said no one else except for monkeys and human could kill him. This is because he believed that both these living beings were not capable to kill him.
This was his mistake and he suffered life as a result.
3 - The third and final thing Ravan told Lakshman that one should not reveal one’s life secret to anyone in the world. Here also Ravan made a mistake as Vibhishan knew the secret of his death. Ravan knew this was his biggest mistake of life.