Consequently I dont believe it was or should just be a matter of "bide your time", "wait out the years" but I do think there is a certain point, if they had waited that long and the relationship had endured then there is less of an argument, a certain sort of maturation has taken place.
I think you're characterisation of those years, the vulnerability and the fact that everything is so, so, so significant in a way which the passage of years really and truly does change should be something which people are giving more consideration to and are not. It was a difficult enough time in life going through all that without half of the sexualisation and ramped up expectations of experimentation etc. that there are today. I'm actually glad that deciding what bands I liked was as important to me as what it was and I wasnt already obsessing what what girls I wanted to get alongside when I was in my late teenage years, let alone younger.
So far as sex being a big deal, it is, the sorts of imprinting that takes place when the brain is given the bums rush by a combination of biochemical overload and emotional flooding involved in sex is not nothing, its not something which gets discussed in sex ed either, hey, if your desperation to not be the last person who is sexually active drives you to shagging some one you'd spur sober, to put it mildly, dont be surprised if all your life you're unwittingly and unconsciously attracted to people who look the same way.