Five sure signs of maturity.

Impulse control

Impulsivity is a tendency to act on a whim and impulsive actions are typically poorly conceived, prematurely expressed, unduly risky, inappropriate and often lead to undesirable consequences. Mature people control their impulses and think before they do anything as they are aware that every thing they do will have one or the other consequence and therefore their thinking is almost always strategic.

Peer-pressure proof

Mature people rarely fall for peer pressure or social norms if it goes against what they believe in or what they want. They believe in being able to make their own decisions and not just follow the norm. They are also very accepting of this similar behaviour from other people.

Foresight

Mature people are able to think ahead, often far ahead in future because they believe that if one can do something in the present that will surely benefit them years from the present, it will be strategically rewarding.

Grace

Mature people have the ability to handle all kinds of situations with grace whether it is graciously accepting their wrongdoings or graciously apologizing or graciously accepting that not everything is about them. 

Patience

One of the surest signs of maturity is the ability to remain patient and thoughtful in dealing with people. Mature people can successfully compartmentalize their personal feelings from their logical brains.