I stopped by my old school the other day to pick up my Little Sister and take her to buy yarn (her mom is having a baby so I'm making a baby blanket). When I parked and started walking, this kid - actually tall young man - ran across the lawn, arms outstretched. I honestly don't know when someone has been so visibly excited to see me. It was my student from third grade who met President Obama. And ate lots of hamburgers while in DC. (in reading his essay, that seems to be what stuck out for him).
This kid is now in 8th grade, so probably 13 years old, has lots of friends, and appears to be a leader among his group of friends. He is tall, confident, and outgoing. And he's not embarrassed to be running to hug his third grade teacher in front of the whole school.
That's worth it all right there.