Not sure how I should feel

My son came home from Chicago for Christmas.He has been out since September, first boot camp, than school started for him.  He was very happy to come home and we were happy to see him.  He looked more mature and reasonable.  Then he spend a few extra hours with his friends from high school and when time came to leave, he got all emotional and upset.  He was not ready to go back.  I understand that, but to me it felt like he was missing his past.  I told him before and then again, that high school is not to pinnacle of his life and he needs to look forward to the future and not the past, that he needs to focus on the school and the opportunities that will be presented to him.  He chosen his path and we were and are supportive of his choice to be in the Navy and very proud of him for going into service, but I still have to be the cheerleader.  I was observing his friends during his visit and the only feeling that I had been how great that he is out of here.  For some reason he did not surrounded himself with kids with ambitions and that was effecting him.  I know I can’t push my dreams on him, but I also will not let him just drift in life.  It is bothering me that there are so many people that he is surrounded by now that have goals and dreams and responsibilities and all he can see is the past.  I hope that once he gets back into the routine , he will get his priority streight.  I understand it is hard to be away from the family, but on the other hand, how you going to learn to “swim”?
I have to confess, before it was my time, I was not really sure why parents were so determined to get their kids out of the house and now I know why.  It  is obvious to me that talk can go only so far.  We can try to tell our kids how life is, and how to navigate, and how to balance the check book, and how to do laundry, but untill they actually do it, face it, bounce the check and get all their white clothes blue, they will not believe us, at least most of our kids.  So I have to admit here that I am very glad my son is out of the house and he is in the real world where his actions will most defiantly create reaction and consequences.  Save sailing child, I will still be your cheerleader.