Woah there, there is a lot going on here.
First, there's a huge world of difference between a kindergarten and 5th grade student; simply because these two student bodies populated a building at one point does not mean much. They're really only relatable to you because YOU see them in your environment; that's very superficial. I highly doubt that a 5 year old kindergartener or 6 year old first grader would share the same interests or be as aware of the world in the same way a 10 year old would be.
It seems like you're very focused on the youngest age limit it would be acceptable for you be attracted to. And there seems to be a feeling of discontent that the minimum age increases as the years go by. That's very concerning, if I may be honest.