One afternoon we were in the kitchen and I was making his tea. While I was pouring water from a pot into his mug, suddenly he asked

Rob: "Is the water in that pot, hot?"
Me:  "Yeah, why?"
Rob: "How that it can be?" He touched the pot body few times then he said 

Rob: "The pot is cold!"
Me:  "Don't worry, the tea is hot".

After dipping a teabag, I gave him the mug and he was amazed when he felt it was very hot. 

Rob: "It is unbelievable, there is no plug on and how come the water stay hot inside the pot. It must be a 'MAGIC POT'".

Me:  "Hahaha!(Laughing Out Loud)". 
Then I explained to him

Me: " It is a vacuum flask to keep the temperature hot or some people called it thermos. I boiled water and put in it last night."

Rob: "Oh!, I've never seen anything like that..". 

This is the magic pot (flask) that we were talking about:

Honestly he's been using microwave or electrical pot to make a drink and he has never seen anything like big flask or thermos in his entire life. He called it magic pot since then. He is totally funny!