I don't blame the people in the train for looking at us strangely when the following conversation took place yesterday as we traveled up north through Sweden and saw more and more snow:
Linnea: - Mummy look! Snow!! Look! More snow!
Me: - Yes, it's nice, isn't it?
Lucas: - Why is there snow..?
Me: - Because it is winter.
Linnea: - What is winter?
Me - ... Well... :)