Why do schools correlate age with maturity

Does maturity have anything to do with age?

Hello,

Some say it is strange to be friends with people aged 15/16 as a 19-year-old, for example. Others think that this is the most normal thing in the world or that it can even be cool to do something with them. Because between the ages of 13 and 16 there is usually a lot of talk about childhood love, first relationships, experiences and also about boys in general, which can also be of great interest to 19-year-olds.

Personally, I tend to be one of those people who would rather do something with 15- / 16-year-olds for these reasons (mentioned above) than with my peers. or even older ones. Unfortunately, it is the case with me that I am either ignored or simply unpopular with almost all 15, 16 or 17-year-old young people I like. There are some people with whom I talk normally, but those are more people who only want to talk to me when they have no one to talk to either because their friends are gone or the like.

I recently approached two out of three young people about it and they said it was nothing. Unfortunately, I don't know myself what exactly it is.

Is it embarrassing and strange at the same time when you, as a 19-year-old, are ignored by most of the younger ones / are almost always unpopular with them?