Being mature is not the same as growing, or “becoming of age”.
To become a mature person is to learn various important things in life, and to develop ways to deal with situations in a proper way.
It is avoiding excuses, accepting responsability for your actions, making an effort an remembering important things and keeping track of your duties, being responsible with what you own and what you’ve been lent, remembering to give it back on time. It is being patient and searching for the right solutions without losing your temper when terrible, unfortunate or disastrous situations come along.
Drinking alcohol to deal with ones ‘pains’ or to escape from situations is an example of immaturity. Same as doing drugs for the sake of fitting in or being with a group. And the same also applies to going or doing something to avoid facing a certain situation, when by facing it you can end it’s possible future consequences.
Mastering these issues will favor you in life, allowing you to become a better person, serve society, yourself, your family, and be happier in general.