Health. Try not to lose it. Physically of course, not mentally. If you lose your mental health completely, you will be happier :) You are questioning the meaning of life. Once again, what makes you happy? If you decide one that, you can choose your lifestyle. For example, if helping others make you happier, you should live like Amélie Poulain :) For some people it is having fun (alcohol, sex, drugs). I can guess that you're not that kind of person. For some others, it is the success in business life. Sometimes it is to start a family, have some children etc. The meaning of life changes from person to person. You are the only one to find it out.