What has happened to my little boy?

As you all know, Ethan started 1st grade last week. Well, this week he started riding the bus! I feel like he is growing so fast. I am happy that he is doing so well and loving school, but the selfish part of me is sad because I miss my baby. In the mornings, he walks to the bus stop with our neighbor and his daughter, and in the afternoons he runs home from the bus stop. I'm not sure why, but this bus thing is harder for me than him starting school!
Monday, he had a class project. It was called an All-about-me bag. He had to bring in a bag with 3-5 items that he would show to the class to tell about him and his family. He took in his Colts helmet, his Navy shirt, a stethoscope, and photo album with pictures of our family in it, and a golf ball! He took the Colts helmet to tell them he was from Indiana and he loves the Colts (especially Peyton)! He brought the Navy shirt because Daddy is in the Navy. He showed the stethoscope because Daddy is a doctor and Mommy is a nurse. The golf ball was to tell them how much he likes to play golf, and that he got golf clubs for his birthday. The photo album was to show the class his two little sisters. His teacher called me that afternoon to tell me how impressed she was with Ethan's project. She said that he has been very quiet the first few days, but when he got up to talk about his project he just came alive. What a joy it is hear that your child is doing well and growing! So again, I ask the question, what has happened to my little boy.........how could I forget, he is growing up!