I'm sorry but I don't buy into all this Halloween thing. When I was a kid we never went trick-or-treating; it was just something we saw on American TV shows. MLYW thinks that she used to do it on 31st October as a child. But I think that was probably just her Dad's excuse to dress up and scare people!
Actually, her Irish heritage probably has something to do with it too. Trick or Treat started out hundreds of years ago as 'souling'. The poor of the parish would go around the day before All Souls Day, begging for food in return for which they would pray for the souls of the dead. This ancient tradition, once commonplace all over Europe seems to have been supplanted by Guy Fawkes celebrations in England. Why ask for sweets when you could get a "penny for the Guy" and buy fireworks, to be stuffed up a cat's bottom to amusing effect?
The 'souling' tradition seems to have stayed current in Ireland though, half-term holidays coincide with Halloween, so the kids get a week off school to play pranks and cause mischief. The celebration took root in America after the huge wave of Irish immigration in the 19th century, eventually becoming the now familiar and annoying tradition of extortion with menaces in the 1930s which started turning up in England again since the 1980s.
I'm preparing for the evening by putting up the blackout curtains and turning down the volume on the TV. Shhh... If we all keep quiet, they'll soon go away...