My lil' 4-month-old

My little (big chunk) boy is already 4 months old!  Time goes by way to fast.  He can roll easily both ways and is trying to get up onto his knees.  Matthew also already weighs 19 pounds!  He is always laughing and smiling and just loves his sisters.  He loves to grab the kitty and try to put him in his mouth and just stroke his fur.  I am so blessed to have him and his beautiful sisters.  But can someone tell me why they all have to have Daddy's hair and eyes?!  So not fair :)