Laura: Mom? Why is my barn dusty?
Me: Because it sat for a long time without you playing with it.
Laura: But why is it dusty?
Me: There is dust in the air and when something sits still, it collects dust that falls out of the air.
Laura: Can our skin get dusty?
Me: No, not really. Because we are always moving.
Laura freezes and sits totally still for a time, just sitting there smiling.
Then she looks down at her arm, feels her arm and gets this big smile on her face.
Laura: Mom! Feel my skin! It is dusty!
I feel her skin. Uh no. Not dust...
Me: Laura, that's not dust. That's dried snot. You need to use a kleenex.
Laura: Yeah, you're right. It's swot. I will get a kleenex when my arm is full.
I grimace. She smiles gleefully and says: Of dust Mom! Not swot! and runs away laughing.
Welcome to my world.