Mind of any human being is very complex. All through the history of human kind people have tried to map this mind and continuously failed. Inside the mind is the most vital feeling of each person the Ego. All people need ego. Ego at a normal level is the self esteem. Every human being tries to present him/herself in a nice way in front of others. This presentation of the self becomes very important when it being presented before the opposite sex. Each and every person has a negative quality in him, but when he tries to present himself to others, he tries to avoid them as much as possible. It is a very natural action of any person to try to create a good impression about himself to others. This is at a very basic level i.e. when your ego is under control. In this state at least a person acknowledges his negatives and hence tries to hide it. But when Ego is beyond control and the presentation of the self is filled only with assumed greatness of the self. The mind never acknowledges the negative the person has and hence completely ignores it. It doesn't try to hide it, rather ignores the negatives as if they never existed.
This state of uncontrolled ego is explored by Kamban. Kamban's Ravana has won over the world. He is the supreme lord and has defeated every one else. His ego is beyond control as he thinks there is no match for him in this world. Yet he is normal human being. He is in love with Sita. He is meeting Sita for the first time and Sita is alone(yeah his plan worked perfectly Rama and Lakshmana was behind the deer). He assumes the form of sage and visits her. As sage he speaks greatness of Ravana (which is offcourse himself) and tries to seduce sita through words( as surpanahaka did to Ravana by describing Sita'a beauty). The whole episode takes around 20 stanzas. But I would like to illustrate Kamban's psychological depth to his character Ravana through one of the stanzas. http://karkanirka.wordpress.com/2008/11/22/ravana-kailash/