Fact
Fold a piece of paper 42 times and it reaches the Moon
In principle. In practice you will stop at about seven.
Each fold doubles the thickness, so growth is exponential. Starting from 0.1 millimetres, 42 doublings exceeds 400,000 kilometres. The point is not the paper but how badly human intuition handles exponential growth – the same failure that makes epidemics and compound interest so consistently surprising.