Have you ever walked into a room and immediately forgotten the reason you're there? A solid thought convinced your legs to move, but by the time you reach your destination, you realise the thought has abandoned you en route. No, it's not dementia. It's the doorway.

Impress your friends (and potential dates) by being able to answer such questions as:

- Why the sky is blue?
- Why is it dark at night?
- Why does lunacy erupt under a full moon?
- What's the truth about Spinach and Popeye?