Death

[Ace Otana]

We've been dead for many billions of years, we then get a lucky chance to live and then after that you go back into oblivion but this time for all eternity.

That's an interesting philosophical point. If the Universe has brought you into existence once then why can't it do it again and again and again, given enough time.

In legal terms there is already a precedent so we know that it's possible.

{ thinking }

I guess it's because of that fact that this person that is you who has this unique personality with it's own unique love and hate would never return. The things that make you, as in the person with this exact personality and memories couldn't possibly exist twice as the same person. You cannot extract memories of another into a new person. It's the personality and the memories that you hold that makes you unique.
How can one's personality at least be transferred into a new person? If your personality and memory cannot be transferred and is only destroyed then in a sense you are truly gone forever. Because it's the personality and memories that you carry that makes you, you. Without them, you'd just be another person.

This be why once you die you die forever. Would you carry the same name, views and such in a new life? Even if so, it would be incomplete without your memories.