to answer this question, we need to take a journey back in time. the modern human mind, with its amazing ability to analyse, plan, create and communicate, has largely evolved over the last hundred thousand years, since our species, homo sapiens, first appeared on the planet. but our minds did not evolve to make us feel good, so we could tell great jokes, write sonnets and say 'i love you'. our minds evolved to help us survive in a world fraught with danger. imagine that you're an early human hunter-gatherer. what are your essential needs in order to survive and reproduce?