Fat Tuesday is most famously celebrated in New Orleans, where the 10 days before Shrove Tuesday are marked by masked balls, parades, clowns and some wild behaviour. Wild behaviour features in other festivities around the world, such as the Rio Carnival and the German Fasching, which are notable for their riot of colour, dance and song. Riots, in fact, frequently accompanied medieval carnivals, especially after mass ball games between opposing villages. Masking, clowning and mock fights still characterise carnivals today.
Shrove Tuesday is the last day before Lent, the 40 days (not including Sundays) that precede Easter - and which are meant to echo the 40 days Jesus spent in the wilderness. "Shrove" derives from the Middle English word "shrive", to confess sins and be absolved. In the Middle Ages, Christians would go to confession before embarking on a penitential period of Lenten abstinence beginning on Ash Wednesday. The ash worn on the forehead was a sign of penitence. Meat, eggs, fat and sweet things would not be eaten - rather handy as they were probably in short supply at the end of the winter. Pancakes were a feast before the famine, a way of using up all the eggs and fat in the house.The name of carnival may derive from the Latin "carne vale" meaning "farewell meat".
Perhaps the fact that these celebrations are so widespread shows how deep is the human need to assert the life-force. Or perhaps we just like pancakes.