I delivered this lecture at UCC during the Cork Lifelong Learning Festival and again in Knocknaheeny Library, Cork, as part of the "Learning Neighbourhoods" initiative, which formed part of the Cork UNESCO Learning City programme. The lecture was attended by primary school children, secondary school and third level students, and members of the general public. (In 2015 Cork achieved a UNESCO award as a Learning City, one of only 3 cities in Europe and one of 12 cities worldwide. This award recognises Cork's continuing excellence and commitment to lifelong learning.)