From an early age, my local library was a sanctuary for me. It was more about looking than reading. During visits in my teens, I acquired the guilty pleasure of 'liberating' book jackets from their hardcovers. In 1963, age nineteen, I was thumbing through some new arrivals on the shelves and pulled out this book. I was overwhelmed by the stark simplicity of its cover, just two colour line and an idea. What it taught me was that being limited expands the imagination. Styles fade, ideas endure. The cover was designed by Keith Cunningham (1929-2014). Fifty-eight years on, this little gem still gives me a thrill.