big questions, small and artificial answers

A friend that I used to work with asked me today what do I think is the purpose of life. We were in a Chinese restaurant, full with people that were celebrating, with woman that had babies in their arms and with husband that discussed business with other husbands. This man is part of a very different culture, he was raised in a communist rein while I was raised by people that were also raised in a communist rein, so practically from a "western" point of view, I had an advantage, however this man shocked me when he asked me this, and I forgot to mention, today was his birthday, we were celebrating him. He just asked me- what is the purpose of life for me. I said that I read a lot of philosophers, and they all tried to find a response to this question but they did not. Some of them just gave up, some of them just keep trying until they knew that they have no reason to know, maybe if they knew they would die instantly, maybe life would loose its charm, or just maybe they will seize to become. After smiling I asked, why do you ask, and he told me, because I am just thinking about this. I said that I just don;t know, I did not thought about this things for ages, but if would be to give him a simplistic answer that would be" finding balance". Then I walked to my flat, again i forget my keys, my sweet and lovely flat mate had to come and pick me up, I went into my room and I thought about the people that think about this big concepts of life and death and the purpose of life, and I felt limited, I felt that at a certain point since teen years and present I've given up this big thought, I just said, leave this thoughts to bigger man, but as my friend asked me I understood that this balance that i look for in my life has to have a more specific definition, I could not explain exactly what I mean by balance, I could not explain why is this balance so important for me, except for the fact that at present I feel its lacking from my existence. I could not tell him because I do not know what exactly is more important for me. I told him I want to balance my personal life with my professional life, but when this words touched the air, I remember a discussion I had years and years ago, when I was just 15 or 16 years old, with my best friend, at her kitchen table, she told me I don;t want to be mediocre, I am scared of this, but just one year a go she told me again, its inevitable, I want to be happy, I need to be mediocre. Now its my turn, later then her, but I swear I am so afraid of being exactly what I tend to be- mediocre. And this balance- to have a good personal life and an average professional life, it's exactly this. A  professional successful person, is most times a person without balance. Now it depends how you judge success. My mother sees her life as a success, because she manage to raise my sister an me, and she did it well, she has a family and she knows that its a solid thing. This is her success and for her this was and is her purpose. Getting into my dissertation topic, and discovering a lot of flows, I discovered new flows in my way of looking at things, my friend asked me a simple but yet so complex question, and then another friend told me " when I will grow old I want to be happy", actually the purpose of life is to be happy, but the question, the multiple unending questions remain... What makes us happy? and for how long?