h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

From the age of zero to around four years is suposedly the child's most formative learning period, during which they (generally, but not always) become mobile, begin to communicate and learn to control their bodily excretions. These are, of course, very useful skills, but some children develop just that little bit too quickly and somehow manage to combine all three, producing children who excrete while moving and then want to discuss it. This, naturally, leads to difficulties when children attempt to interact with adults who rarely enjoy discussing excretions. In later years, however, many male adults find that the combination of walking while excreting liquid waste can prove extremely useful, say, when walking home from the pub through the woods on dark evenings.