Teach Your Children Well

Sometimes you just wish for wisdom.
"I want to count the money in my piggy banks and go buy a new toy," chants Mia over and over. Christmas was a week ago and she has acquired a taste for fresh packaging, that plastic smell.
"Mia, there are children who don't have as much as you do."
"Let's go to the store and buy them things!"
"Mia, if you don't like your old toys, we should give them to children who don't have what you have." (Wait a minute. What am I trying to teach here? Generosity or frugality?)
"We can give them this," she says, pulling out a tiny piece of inconsequential crap out of the toybox. "Or this," she adds, holding one of Eleanor's baby toys.
"Um, Mia, giving to others doesn't really mean much unless you give something that has meaning for you." (What? Is this a lesson about Anti-materialism? Giving? I'm confusing myself – what's she going to get out of this?)
"Okay, I know! We can give them this!" And she holds up a chestnut plastic horse. It's about twelve inches long, one fetlock is missing, another is held in place with blue masking tape. I received this horse as a Christmas present about thirty years ago and she knows it.
"I'll feel so sad when I give this horse away," she says sincerely and I'm shocked, not only by her utter lack of guile, but by her accidental logic and her unconscious grasp of irony. She just turned the tables on me and asked me to feel what she is feeling.
How do you do this parenting thing anyway?