It is one thing to study eschatology; it is another to be so convinced that you, yourself, will be the personality that it centers around. From Ahmadinejad and the Dawning of Messianic Times:
Since the late ninth century, the Shi'ites have been expecting the emergence of the hidden imam-mahdi, armed with divine power and followed by thousands of martyrdom-seeking warriors. He is expected to conquer the world and establish Shi'ism as its supreme religion and system of rule. His appearance would involve terrible war and unusual bloodshed.
Ahmadinejad, as mayor of Tehran, built a spectacular boulevard through which the mahdi would enter into the capital. There is no question that Ahmadinejad believes he has been chosen to be the herald of the mahdi.
Shi'ite Islam differs from Sunni Islam regarding the identity of the mahdi. The Sunni mahdi is essentially an anonymous figure; the Shi'ite mahdi is a divinely inspired person with a real identity.
However, both Shi'ites and Sunnis share one particular detail about "the coming of the hour" and the dawning of messianic times: The Jews must all suffer a violent death, to the last one.