Why did Jesus give Peter the Keys to the Kingdom?

We are told in the Gospel of Matthew (16:19) that Jesus told his disciple Peter that he will give him the keys of the Kingdom of Heaven.  I was wondering, why Peter?  Then it hit me.  If you were standing at the gates of Heaven, wanting to get in, who would you want holding the keys?  I would want someone who had learned how little he himself deserved to be in Heaven, and therefore would look for whatever excuse he could find to get as many people as he could into Heaven, also.  Peter fits that bill very nicely.  After all, he denied Jesus not once, not twice, but three times.  Jesus forgave him.  That's the kind of guy who would know how little he deserves to be in Heaven, and who would do whatever he could to get everybody else in.  I wonder if Jesus knew that's the kind of guy Peter would be before He gave him the keys.