My baby is 4 months!

I can not believe Alex is 4 months old. Where has the time gone? He is such a wonderful baby. He is just mellow and chill. He loves to smile and it doesn't take much to get him to. He is starting to think that Isaac is pretty funny. He smiles and giggles when Isaac talks to him. He is a great sleeper. He only takes a short nap in the morning, but takes a 2 1/2-3 hour nap in the afternoon. He goes to bed about 6:45pm, wakes up at 10pm to eat and then he is out until 7:30am. He loves his hands. He can't stop staring at them and putting them in his mouth. He is learning to grab onto things. The funniest is when he got a fist full of his own hair and started screaming, but still didn't let go. I took him to his 4 month check up and his doctor described him as perfect. He is meeting all of his mile stones and his head is looking a lot better from physical therapy. He weights 15lbs. 8oz.(67%) and is 26 inches long(85%). So he is a big boy just like his brother.