I think I know what this means, but I'm not sure. Can you put it into pin yin for me? :) We are happiest when we go after our dreams. If we just study, work, and play, then our existence would have no meaning. Animals can do all of that. Ambition is what separates us from the animals.

生活本身就是一种存在,存在好象本身就是种意义. 三多同志说过, 有意义就是好好活，好好活就是做有意义的事.

I was looking for the same answer for many years myself, and finally found a great deal of peace in this aphorism: "The meaning of life is to give life meaning."