nothing matters

Because:

• goals are arbitrary: achieving a goal, or failing to, doesn't really matter because the goal was arbitrary anyway.
• From the perspective of the universe, human affairs are insignificant purturbations of a tiny pale blue dot. Even from the perspective of humanity, my affairs are insignificant. If something seems important, just shift your perspective out by a few orders of magnitude, until it vanishes. The second perspective is just as valid---and in some sense less arbitrary, less particular than---the first. So how can we really say the thing we originally focused in on was important?

It's tempting to fall into nihilism. Yet we can view this as freeing, rather than depressing. It allows us latitude in choosing the purpose of life.