Dh has been reading the Emma books to the girls at bedtime. Emma is an 8-year-old living with her mother. They have a friend's 4-year-old little boy staying with them.
In the story, Emma doesn't like the little boy. They don't get along. Dh tried to explain to the girls that it's because Emma is older, so she'd rather play with kids her age and she finds the little boy obnoxious. The girls don't understand. They're homeschooled. They play with kids of all ages and kids of all ages willingly play with them.
Here's the gist of the reply dh got to his attempt to explain the age thing:
But Cecilia is 8. We're little, but she plays with us. She likes to play with us. Her sister is 9 and she plays with us too. We like playing with them. They have beads. We play dress up with them. We put on fashion shows with them.
At a field trip in October, the mom of the aforementioned sisters summed it up nicely. The kids were all playing on a haystack and a boy of about 12 called for another little boy to play with him. This friend of mine asked, "In what public school would you find a pre-teen willing to play with a 4-year-old?"