Life of Muhammad

In class today, we talked about the life of the Prophet Muhammad.  His story was very interesting in many aspects.  I felt that the most interesting part, however, was when he went along with his uncle up to Syria.  A monk saw them coming and went to talk to them.  The monk told Muhammad’s uncle, Abu Talib, to protect Muhammad from people who would try to hurt him because he saw that Muhammad was indeed the final Prophet.  I was confused about this, however.  Did the monk tell Muhammad that he was the final Prophet?  And, if so, did Muhammad believe this guy?  The reason I’m confused is because the monk knew he was the final Prophet, but nobody else knew.  Therefore, if Muhammad had this knowledge, how come he thought he was going crazy when he had his first revelation?  If he didn’t know then I would understand that this would be a very scary thing to happen to somebody.