For over 25 years, on the first Sunday in May, thousands of people from more than 120 countries get together and celebrate World Laughter Day. And what do they do? They laugh and laugh … and laugh! People from 'laughter clubs' in cities and towns across the planet invite their friends and family members to join them, usually in public spaces. One very large 'laughter event' took place in the year 2000, when 10,000 people of different ages and backgrounds gathered in the Town Hall Square of Copenhagen, Denmark – to laugh!