When I was serving in the army as a conscript, there was a storeman who looked very young. At first I thought that was because he had a baby face. I later learnt that he was only 17 years old, a participant of a special scheme that allowed males aged at least 16.5 years old to opt for an early enlistment, with parental consent. Most of us were called up for enlistment upon reaching 18. Thus that made him the youngest soldier in the unit. But from what I heard, he did not receive preferential treatment.
There was once I got a chance to talk to him when I went to the store. I asked him the reason for the early enlistment, as most people would still be in school at his age. He told me he did not do well in school, and employers were unwilling to hire him for full-time jobs due to his age. So his parents thought it would be better for him to enlist early and to get a job after his stint in the army. I did not ask too much in case he thought I was invading his privacy.