Out of the blue, coming home from swimming tonight:
J: How come people, like Daddy, try to not sneeze?
Y: What do you mean?
J: When they need to sneeze, they go like this (puts his arm up in front of his nose/mouth area and stifles a sneeze into his arm).
Y: Wow. Good question, Josh. I don't know. I never try to hold back a sneeze (it's true) because sneezes feel good. If my nose is itchy and I sneeze, I feel better after I sneeze. Don't you think so?
J: I tried to hold back a sneeze today. In the playground at recess. I put my arm up and went like this (does the same action as before). It hurt my nose to hold back my sneeze. That's why I want to know why people do it.
Funny how asking a question with a seemingly obvious answer makes the answer seem less obvious once the question is asked!