Do you think seventh years at Hogwarts have a muck-up day? On the last day of school, half the students have swapped uniforms, timetables and common room passwords with friends from other houses and are steadfastly insisting to the teachers that “of course I’m in Slytherin, what do you mean I’m a Ravenclaw, you insult me”. Meanwhile, someone’s enchanted suits of armour to act as bodyguards for random first years, who can’t even enter a classroom without a vaguely panicked pile of metal clattering along behind them and leaping on potential attackers. Sir Cadogan has been convinced to battle the Fat Lady for possession of the Gryffindor common room (the Fat Lady is a surprisingly vicious fighter) and nobody can get through the portrait hole. In the spontaneous sleepover that ensues in the Great Hall, a group of over-emotional seventh years huddle together, clutching Butterbeers they’ve smuggled in from Hogsmeade as they sing “Hogwarts Hogwarts Hoggy Warty Hogwarts” one last time.