What I mean by maturity is how one behaves in situations or how one handles situations. There could be various aspects of maturity and various form for it also. Different forms of maturity is like, how one behaves in happy moments, sad moments, frustrated moments, angry moments, etc. What I mean by different levels of maturity is, when they show the matured behavior.
For example, when taking a happy moments, showing maturity will mean not to make promises beyond our capacity, when talking about victorious moments, showing maturity will mean being modest, in angry moments, being mature will mean the ability to keep our mouth shut, etc. I would like the tell my opinion about the last case, different level of maturity in case of anger.