Ravan was called as Dashanan, meaning the ten headed one. His ten heads made him superior in the world and were the reason of his power and strength. They reflected his thoughts, personality and character which in fact are like warning lessons for mankind for not deterring the right conduct.
As he was an ardent devotee of Bhagwan Shiv, he once severed all of his heads to appease him. Bhagwan Shiv was immensely pleased with his sacrifice and granted him back the ten heads and with that, great power too. However, with all the knowledge of scriptures, Vedas and Astras , Ravan could be anything else, but a good individual.
Ravan grew to be an egoistic demon, terrifying the worlds by and forcing them to comply with him. He disturbed the balance of Dharma in the Universe, and Bhagwan Vishnu incarnated as Shri Ram to get the world rid away of him. The ten heads, powers and might of Ravan were of no use in his battle with Shri Ram and thus he succumbed.
Being a scholastic personality, the ten heads initially symbolised the four Vedas, and the six Sastras in which he was well versed with. But he never understood the true meaning of what he learnt, and hence the ten heads came to be the representations of ego, anger, attachment, greed, hatred, fear jealousy, lust, and insensitivity, finally regret. The negative emotions overpowered his intellectual capabilities and thus in spite of being the possessor of great knowledge and intellect, it was no use.
Ego made him never pay heed to anybody who advised him not to go against Dharma. Anger made him blind and he never saw beyond Shoorpanakhas’s plan of involving her own greed and revenge into the plan of abduction of Mata Sita. Attachment towards material desires made him drive away his brother Kuber from his city, and keep all his riches including the Pushpak to his own.
Greed is the root cause of his doom. To kidnap other person’s wife and trying to make her his own depicts his greed for desires. The hatred for Shir Ram never made him look beyond it and realise his sins. One who is tormented by greed and hatred always has fear of the opponent. The moment Ravan kidnaps Mata Sita, a sense of fear enters him as he knew that what he was doing was wrong, but he tries all ways to subdue and not show it.
Ravan was jealous of Shri Ram in all ways. This jealousy drove him mad, and he committed many mistakes from which he could never recover. Ravan’s curses were a result of his lust for women. He regarded women as things of luxury and beauty but never saw divinity and the piousness in them and hence his lust on Mata Sita led to his doom. In spite of repeated advise by Vibhishan, Mandodari and finally even his dear son Indrajeet, Ravan stayed insensitive to return back Mata Sita to Shri Ram, and thus he is finally left with regret when he sees all his clan perish in front of his own eyes. Ravan, in fact imparts things which should be avoided for destruction and thus, one learns the Not to do things from Ravan.