The English philosopher John Locke famously said that 'Reward and punishment are the only motives to a rational creature'. And from the gold stars we give to our children, to the rewards we administer to ourselves everyday, and the religious stories about paradise after death, we typically see reward as central to our lives. But rewards can be psychologically damaging, addictive and cause a dopamine imbalance in our brain argues world-leading Stanford psychiatrist and author of Dopamine Nation, Anna Lembke. We need to learn to be content with absorbing experience in the here and now and living in the present moment.