As a tour manager, Chris Sheldrick was tired of everyone getting lost. Standard street addresses weren't ever precise enough, and GPS co-ordinates often got misheard. So, Chris and his co-founders invented a new global address system, what3words. Seven years on and what3words is being used across the world for all sorts of things, from helping the emergency services find the scene of an incident, to getting fish-and-chips delivered on the Isle of Man. Chris Sheldrick, Co-Founder and CEO of what3words, tells Claudia Winkleman about hiring adventurers, making deals with the Mongolian Postal service and why you'll often find him staring into space.