Slate Magazine published Last Notes an excellent piece about the final words (and works) of some famous composers. Part of the thrust of the piece was that there is an end to life, and how the creative artist deals with it.
Personally (after a bout with cancer), I'm comfortable with a life that has a beginning and an end. Like a good story, the limits help give it meaning and definition.
I've thought quite a lot this past year about numbers. Because my life has an end point, I will only write a set number of blog posts, for example. I don't know how many, or when I'll stop, but at best I can only keep writing till my dying day (unless technology advances sufficiently to write from beyond this life).
And that finiteness helps me appreciate things more. Some final events (like the ones in the article) will be marked -- last day of work, last day owning our current car, last mortgage payment -- but some won't. I will hear my favorite song for the last time at some point -- maybe I already have. At least I can say I enjoyed it every time it played.
All of the normal daily routines will stop at some point, either by choice or circumstance. But that's all right. Because that will give them meaning. In a straight line that extends infinitely in both directions, there's no way to tell which points are the best, because the set of them is open-ended. With a finite number of days, it's possible to mark the lows -- and the highs.
Don't worry -- nothing dire in my personal life prompted this post. Just an appreciation for the arc of the story.