There are so many definitions of being happy in this life. In fact, everybody has a different view depending upon his or her practical life experience which surely reflects on views. As far as my notion is concerned
a person can be happy when he understands the truth of life. For Instance, this life has to end at somehow. So whatever we will earn will be useless to certain point except the good deeds we performed in life which helped others. Helping others and pleasing others gives a real happiness and satisfaction. Attainment of your targets and getting lots of money does not guarantee to be happy.
To illustrate, there are plenty of people in the world who have lots of money but they are not happy.as this life is not eternal so we had better think that life after death is the real life and this life is just a little time in which we have to try to help others morally. Every person has his own circle of people like family, relatives, friends, colleagues and in all the relations more important is relationship. We are supposed to value people rather than things. For strengthening relationship we should be positive minded and believe on acceptance instead of expectancy because positive attitude eliminates conflicts and hatred .circumstance usually make people busy in negative side .that is why people are not inclined towards creativity and development in personal and professional life.
We may enjoy each and every moment if we have no greediness, selfishness. I have firm believe, helping and caring others really cherish you.