Flashbacks

I am really finding all of the flashbacks into Vito Corleone's life to be very interesting.  The flashback that we saw today really gave me insight into why he did what he did when he grew up.  I also found it interesting that Clemenzo was his "mentor" and how in the Godfather part I, Clemenzo was working for Don Corleone even though Clemenzo taught him the ropes of the business.  I wonder how Don Corleone moved up in the ranks to be more powerful than Clemenzo because in the flashback, Vito follows Clemenzo around like a lost puppy!