Joe this video makes a lot of sense to me. I did a post yesterday for a contest about my life where it has been to where I am now. I find that if you don't know what your life's purpose is everytime you reach something that you want, you get it and if it feels like its not enough then you want more. So you have not filled your purpose, and like you say time is limited.
For me I think its about happiness, other people tell me I am funny and amusing, and it makes me happy when I see those people happy. So I wonder if this is something that I need to pursue and whether it is my meaning of life maybe??