On today’s show: Zelda la Grange grew up supporting the rules of apartheid in South Africa, but she later became one of Nelson Mandela’s most loyal and devoted aides. She tells us about working and traveling by Mandela’s side for almost two decades. Jonathan Demme, André Gregory, and Wallace Shawn discuss bringing their interpretation of Henrik Ibsen’s “A Master Builder” to the screen. We’ll investigate how interactions between the brain and the world around us can give rise to delusional thinking. Neuroscientist Nancy C. Andreasen looks into where creative genius comes from and why it’s so often accompanied by mental illness.