I am so happy to hear this story. We had a similar thing with my stepson...he was like a lost soul...didn't know what he wanted to do and hanging out with wrong crowd. He decided to enlist, and his 5 years in did him wonders in the maturity area. Although he is still somewhat immature for his age, he has come a long long way thanks to the military.
Blessings on your family, and thank your son for his service!