Good posts. I completely agree that the author missed the idea of puberty being about more than just physical changes and also about mental changes and life experiences. There are a ton of life-experiences people have between 13 and 19, 15 and 19, etc. When I was in my senior year of high school, I had a friend who was dating a girl in 9th grade. My friend was 16, about to turn 17, and this girl was, if I remember correctly, 15, soon to be 16. Also, at my school, 9th grade was not included with the high school, but instead with the middle school. I and some of my other friends felt that this guy should not be dating this girl. His defense was 'I'm not that much older than she is.' To which I replied that that did not matter. He was in a way different place, almost done with high school, going to college soon, whereas she still had all of high school to go, etc. I felt that his behavior was just taking advantage of her, and it was one reason we're not such great friends a few years later. It's not just about chronoligical age and physical maturity, but what mental state you're in, where in life you are relatively speaking.