To start with, who is an adult? An adult is a person who have passed the stage of infantry. That is the stage where he /she could do things without using sense. But when the stage of adult comes in this begin when he or she reach certain age above twenty, he or she begins to think right, differentiate between good and bad, start taking decision on his or her own without the concept of anyone. At this stage he or she knows what he wants, what he wants to become in life and what he or she is aiming to archive in life. Live ur adults life wisely have a great day ahead. source