Great question, drunk or not. Someone once said that the unexamined life is not worth living (Socrates?), and while I would not go that far, knowing who and what you are, and where you are headed makes quite a difference in day to day happiness, as well as overall achievement.
IMHO: Life has the meaning you attach to it. The below outlines my take on this.
A great exercise is to imagine people whom you respect discussing you after you are gone. What would you like them to say?
Is the man they are describing you?
Another is to simply make a list of the things that make you happy. This is not a list of things like cars or other toys, but your personal situation with respect to the world and relationships with other people and organizations. Once you have your list, number them in order of importance to you. How many do you have? Do you have a plan to get the ones you lack?
Ex: Romantic love
Health / fitness
High level of achievment relative to your peers.
I have gone though this process, and it actually told me a few unexpected things about myself. I am not the nicest person you will meet. Often I am rather ruthless when it comes to acheiving a particular goal. But as I sometimes have to explain to people, there is a difference between friendly and nice. I'm friendly.
I have come to realize that for me, life means living the best life I can on my own terms, and maximizing my own happiness. The only limitations I put upon myself is that I will not use force or fraud to acheive my ends. Aside from that, all's fair.
I think that to a large extent, this POV comes from believing that this life ia all we have. So far, it works for me, and very well.
The above is kind of rambling, but it is early on a saturday morning.
What is the meaning of life? Whatever the the fuck I say it is -- It's MY life.