"He said to them, "But who do you say that I am?"
Simon Peter said in reply, "You are the Messiah, the Son of the living God."
Jesus said to him in reply, "Blessed are you, Simon son of Jonah. For flesh and blood has not revealed this to you, but my heavenly Father.
And so I say to you, you are Peter, and upon this rock I will build my church, and the gates of the netherworld shall not prevail against it."
and so began the transformation of a man who started his life as a fisherman. Today, this would be like your mechanic being named Pope. I wonder, how did this happen? How could it? Peter was known for his mouth and his temper. This was no quiet, weak willed, wallflower. Yet, Jesus chose him to lead the Church here on earth. Peter was a natural leader. A man who could inspire strong feelings both positive and negative in those around him. He was a doer. Introspection and contemplation did not come naturally to him. Even when he says, "you are the Messiah, the son of the living God", he is not speaking after years of study. He speaks instinctively, rashly even but with all of the certainty of any theologian today, (and perhaps even moreso if you consider the cottage industry of heresy from people like Spong, Fox, Haight, etc.) Peter as a thinker happened late in his life.
Contrast him with Paul, a man of equal energy but far more cosmopolitan in his upbringing and education. Paul, the missionary the man who after his conversion spread the Gospel in such a way that even the original disciples probably had a hard time keeping up with him. The two most dangerous things you could put in Paul's hands were a quill and papyrus.
Both men started their lives with different names and no idea what God had in store for them. Simon and Saul began their lives very much in and of the world, their concerns were no different from the concerns of many today, family, work, the future. Their lives ended together as Peter and Paul having changed the world, living in it but no longer of it. The "fiat" that they gave God to work His will through them and that allowed grace and the Spirit to enter into them is an example to us. We don't need to change our names, but we can change our hearts.