When u love someone u let them go if they come back then it was meant to be- but what happens ur both married and have total different lives now

I have a big problem! It all starts when I was young I met a boy and we dated off and on for six years but we were always moving so it made it difficult for us to date. Then he decided to join the army so he left for bootcamp. I was devistated and I wrote to him but never recieved nothing back. A ye