Ever since we’ve been able to make tools and use language, we’ve understood that the year is cyclical. Behaviour that’s acceptable at one time of year is considered wrong at another. Throughout the history of civilisation – any civilisation – we keep a lid on some of our desires and urges so that we can get on with each other without things descending into anarchy. And in every civilisation, there’s always a pressure valve that allows us – within a confined space and time – to cut ourselves loose, to party. Whether that’s Mardi Gras, Mexican Day of the Dead or the Glastonbury Festival.
