David: Is this a helicopter suitcase? (He is pointing to a red cross symbol on what does look like a suitcase that is part of the fireboat we are playing with in the bathtub.)

Debby: No, honey. That's like a doctor's kit. If someone gets hurt, it has band-aids and shots and things in it to help them. It's called a first-aid kit.

David: (he pauses for second) So, this is a rescue fireboat.

It takes me several seconds to make the connection. He must have seen a red cross kit on his rescue helicopter, figured that the helicopter part was the transferable information, and then when I explained the tool, realized the rescue part made more sense as the transferable. I love watching his mind work.