Ruth has a strong memory of a story once told by her German language teacher when she was a student at secondary school. Her teacher had attended university in the late 1980s, and took a course on East German politics. On 10th November 1989 he went to class as normal. The previous night, the world had watched the fall of the Berlin Wall, an event that would come to herald the reunification of Germany and the end of the Cold War. At the start of the class, the lecturer made an announcement. ‘Everything I have taught you is now irrelevant’.