Could be that the way the stories are structured or the themes they focus on make you end up as the boy. Or perhaps your characteristics or actions in those situations align with the role of the boy.
Once there was a boy soldier named Tom. He was very young but had to join the army due to the war situation in his country. Tom was initially scared but with the help of his kind comrades, he learned how to handle a gun and perform basic military tasks. One day, his unit was attacked. Tom showed great courage and helped his comrades hold the line until reinforcements arrived.
I'm not sure who the author of the 'Soldier Boy Novel' is. There are so many novels out there that it's difficult to determine without more information.