I don't see where the positive aspect about immortality or even eternal youth lies. I mean, don't you know this problem that you can only do something if you're under a certain pressure? But if you're immortal, you literally have all the time in the world. You can't even get your ass up to learn standing upright.|
And what will you do with all this time? Everything gets boring after some time. And even if you're physically immortal, how should your mind manage all the information you gathered over the centuries? And most of all: How should you stay sane when your constantly bombed for centuries with human stupidity?
But well, imagine that somehow you were able to live during 5 billion years the best imagineable life. What the hell are you gonna do when our sun blows up? Hanging around in the universe? Oh, you're gonna be hungry...