Okay look at it like this Spath, we have to have clear lines for legal purposes regarding age, so for whatever reason we've settled on 16 is the age of consent, you can marry and join the army, not 15 years and 363 days.
BUT, do you think there is a material difference in a person on their 16th birthday to the day before? I think that's what we are trying to say to you, that most 15 year olds are really not children in any sense except technically legally.