I think that learning this in school would have been useful for my whole life. But nobody taught me. I did learn a few things from my parents, but they were not always an example for a harmonious relationship. I did learn a bit during my interactions with school, university and work colleagues and then a little bit from friends or during my different relationships with a partner. Sometimes I learned the hard way, but most of the times I did not improve anything because I did not know what I was supposed to learn.