[Spenner]

Maturity is based on societal expectations in a conventional sense. If you can learn to conform to those and practice good behavior in society then you'll get along with other adults in that society.

But this is learned behavior more than anything, and you will always have individual differences from other people, and anticipate realizations of those differences to be stress, or anxiety, or whatever. These feelings are to be realized for what they are, if you're to learn and live as you should. Maturity is fully realizing that your individual differences need ways of adapting to the society around it-- not something that it fully is nurtured into with school or a couple of jobs. And learning realms of self and identity. Basically once you've explored what you really are as a person, you can learn to let go of things that you need to for optimal survival, and to control emotions you otherwise left to automatically be cycling constantly because of a stressful encounter.