I just put my sweet little 5 year old to bed and we read the book Santa's Little Helper.  He asked me why santa doesn't get any presents.  I told him because he has everything already and he loves to give to little boys and girls...he then said "I bet when santa was little he got presents and he had no idea he was going to be santa when he got older".  I told him that maybe he will grow up to be santa and he looked at me serious as could be and said "NO I am going to be batman"!  To be a 5 year old again.  So innocent and sweet.