Standing in the queue for the subway after being beat in a European tie a few years back, it was cold and wet and everyone was depressed from losing so it was absolutely silent. Then one of the policewomen who endlessly shout "keep to the right" has their horse suddenly lose control, someone in the queue shouts "Woah put the brakes on that thing!" at which point the horse starts running backwards to which the guy shouts "Naw, that's reverse!". Doesn't sound that funny describing it but it was one of those "had to be there" moments that immediately cheered everyone up.