What is the point of celebrating something at time intervals that correspond to one rotation of the earth around the sun? Isn't that completely arbitrary?
So it is with life. Perhaps in the long run we'll all be dead and the universe will cave in, but in the meantime the things we do and say matter, and there is beauty in the world to appreciate. So I went to the boardwalk with my father and brother and we all had a terrific time, and having a good time was reason in itself to do it.
Once you give up the religious/gamers' view that everything you do has a score, you can appreciate things for what they are rather than for any ultimate result.
It's a convenience. ;)