What's with women and age

Let me share my experience and see how many of you can correlate and share your perspective...

When I was in school, talking to girls was awkward. Forget about even thinking of approaching because the facial expressions themselves would keep you away.

Then we move to class 10, the facial expressions turn in a one off smile or a long stare between known or familiar strangers within nothing to speak.

Then some may be in or around the same college and house. I am with my friends and gradually a few girls and then lots of girls. But the stranger friend gives an even interesting expression of 'man this boy was good in school now he has become a slut, what's with so many girls'.

And then cut to the present where I met them at a school reunion. Man I found a completely different girl, so out spoken, relaxed, jovial, some really adult and equally funny jokes, the laughter, initiating good bye hugs and insisting we should plan a trip.....

So the question is daily 5 hours together in school did not help us knowing each other, numerous passing by in college without loking up as if assessing quality of soil didn't help but years being apart made us good friends....What's with women and age.