Lots of the "stories" Ma tells Jack, like How the Berlin Wall Fell Down and Princess Diana are stories of actual events. Even the fairytales, like the mermaid who has a child in captivity, are allegories. Is there anything allegorical about Room itself?

Ma knows that Jack is much wiser than your average five-year-old. His curiosity and passion for knowledge make it easier for him to understand complicated concepts. Ma is confident he'll eventually get them, which is why she shares so much with him, without sugarcoating things, as he gets older.

With every new concept comes new vocabulary. It's a lot for Jack's little brain to process, this whole the-brother-of-my-mother-is-my-uncle thing, so his brain pretty much shuts off and thinks of something much simpler, like lunch.