I wanted to join at 16, wasn't accepted - fair enough. at 17 I applied again, and finally entered just turned 18 - Those 2 years did nothing to curb my enthusiasm, I wouldn't have been exploited, i'd have been doing what I wanted to do.
And to concur with a point above, I spent some time at home after 6 month in service, and even at 18 I was so much more mature than those i'd left behind, they made me cringe!