Wombat: We're not allowed to trade snacks at school any more.
Me: Probably a good idea anyway.
Wombat: Some people got really sick. It's not fair. Also some people put their mouths on their snacks so they can give their colds to other people and then they won't be sick any more.
Me: Um, it doesn't work that way. You're not really "giving" them your cold. You still stay sick.
Wombat: Hey. That's not giving, that's sharing!