'You may fancy yourself safe, and think yourself strong. But a chance tone of colour in a room or a morning sky, a particular perfume that you had once loved and that brings subtle memories with it, a line from a forgotten poem that you had come across again, a cadence from a piece of music that you had ceased to play - I tell you, Dorian, that it is on things like these that our lives depends.'

Oscar Wilde: The Picutre of Dorian Gray