re: If you were truly immortal, how would you pass the time?

I guess the first thing to do would be to invest in some long term high yield investments.

I think at some point I'd undertake a walking tour of pretty much the entire world or at least as much of it as it is practical to get to. And to read pretty much everything there is to read that is even a little interesting.

Although I guess if someone was scientifically inclined one could do things like document generations of descendants of either certain people or animals to see what changes do occur over long terms.