Each stage of life has its ups and downs. Some feel that people are generally happiest as teenagers, while others believe adulthood is a happier time, even though it brings greater responsibilities.
Personally, I agree with the latter point of view.
Life from the teenage perspective can seem very happy. Teenagers live with their parents, who meet all of their needs, and spend most of their day at school, surrounded by friends. They also enjoy long holidays and have plenty of opportunities to relax. In fact, groups of teens enjoying themselves are a common sight in many places. However, one of the reasons they are seen hanging around is that they often have little money and few places to go. Furthermore, at this age, our bodies and minds are still developing, so a lack of maturity can easily get teenagers into trouble. There is also a great deal of pressure academically, with important exams to pass. Therefore, this time of life looks a lot happier on the outside than it is in reality.
For adults, everyday life is a lot less carefree. Living independently means we have to be able to afford accommodation and other expenses. There are also responsibilities associated with work, which often increase with our salary and workload. Working life also offers only a few short holidays each year. Thus, opportunities to relax are brief, so it is not surprising that adults might reminisce about their childhood years. Nevertheless, adulthood is a much longer stage of life, and with maturity comes the ability to deal with any challenges. This is also a period when most adults build their own family, home, and career. All of which brings a sense of personal satisfaction and happiness that is very different to anything experienced in our younger years.
In conclusion, happiness, like all emotions, is a temporary state. Although it is tempting to associate it with being young and carefree, in my view, happiness is a much more complex and deeper emotion that is closer to the contentment more often achieved in adulthood.