handball or harry?

The other afternoon at school pickup the assistant teacher for our kindergarten class cornered me. It went something like this.

Mrs. N: "Did Julia tell you what she's doing at school?" Mrs. N is totally excited.

Me (thinking oh crap!): No...what?

Mrs. N: She's playing handball!

Me (puzzled, thinking this is about legendary family klutziness): Oh...yeah...she mentioned that.

Mrs. N: Isn't it great?

I am obviously so not getting it.

Me: This is a good thing?

Mrs. N: She's not playing some made up game.

Me: Oh.

OK - I still don't get it. Can anyone enlighten me? Because I was that kid, the kid playing made-up games. Granted they weren't made up games in the Harry Potter universe....my games ripped off Willy Wonka (my friend Beth and I had a glass walkway that transported us home from school) and Nancy Drew and a myriad of other stories I made up with my friend Veronica (in which I was somehow always a boy named Peter.). So I'm not getting it because did I turn out so bad?

Granted - I'm a writer on strike but still.

Can someone enlighten me? Am I supposed to squash the imaginative play to play squash?