The deep-rooted cause of almost every problem that we have is related to the circumstances we had in our first fifteen years or so. Exceptions would be trauma, etc. that happened later in your life. For example, if you are angry with someone and you ask yourself why then you might find that it is so because you don't feel respected and why you feel you don't feel respected is probably because you think you are not competent enough and if you go deeper then you might find it was because as a child no one appreciated your peculiarities and you felt neglected. This was just one example. Similarly, all sorts of negative reactions are a result of something that happened in childhood. I haven't yet reached the point where you cure it. I have heard that self acceptance is key to it.