We're at the American Museum of Natural History. We're walking up this big, spiral ramp that has something to do with astronomy. (As it turns out, we were supposed to be walking down the ramp, which would have taken us from the so-called Big Bang through the history of the universe up until the present day. Oh well.) There is a foreign family trudging up along the ramp near us. The little girl keeps running ahead and her older brother keeps yelling, "Pada! Pada!" Each time he yells this at her, she waits until the rest of the family catches up, and then she takes off again.
Sam watches a few cycles of this, then runs ahead of us and says:
MOMMY. TELL ME PADA!
I yell, "Pada!"
She stops. And as soon as we catch up, she yells, GO, and takes off again. We spent the rest of the painful climb playing PADA and GO.
Observant little creature, isn't she?