POP BENEDICT RESIGN BUT WHY???????

The hottest news of this time is that the leader of the catholic church POP Benedict will resign on 28th of this month. He was elected for this seat in 2005 and during his period he made many achievements and did great fro the poor people and countries. But the main question is that on which ground he was going to resign from his post. He is not so ill so far that he can't perform his job responsibilities.
Let us see who will be the next POP and what will he do for the world. At the end we say good bye to the old POP.