Can you imagine what it's like to be someone else? Most of us have empathy: the ability to momentarily put ourselves in someone else's shoes. To feel the emotion they feel. Seeing as we have lived in groups for thousands of years now, it makes sense that most of us can. But how come some people can't feel it (or at least not so well)? Why is it often said that millionaires lack empathy? And when does someone have too much empathy?