@SteveClough Bet the dinosaurs never thought 'We rule the earth'. Just stuck to worrying about food, sex and guarding their territory. Humans are the ones bothered about 'ruling the earth'. Therein lies the problem!

@jjfphd And then, one day, there are no groceries in the shops. No internet, no electricity, no water, no petrol. Money becomes worthless if there's nothing to buy. As a 'fan' of apocryphal sci-fi, the underlying interconnected fragility of our civilisations is a familiar, and disturbing theme.