In devising the sort of projects that lend meaning and a sense of cohesion to our lives, we presuppose that we will live for a certain number of years; say, until we are eighty.
Projects and ambitions such as mastering a musical instrument, learning a foreign language, meeting one’s grandchildren, sailing around the world, and building one’s own house all set challenges that can realistically be achieved within a lifetime.
Projects and ambitions like mastering every musical instrument in the orchestra, writing a book in each of all the major languages, planting a new garden and seeing it mature, teaching one’s great-great-grandchildren how to fish, travelling to Alpha Centauri, or just seeing history unfold over a few hundred years are not realistic: there is simply not enough time to achieve them given current life expectancy.
If [...] one were to live for forty-two years fully expecting to die in a few decades’ time and then take the elixir of life and look forward to infinite existence, one could expect one’s projects eventually to expire, leaving one with a choice between eternal boredom and self-reinvention.
[....]
But this is because these projects reflect a belief about when one is likely to die.
If we could reasonably expect from an early age to live indefinitely, we could embark on projects designed to keep us occupied for hundreds or thousands of years.
Such projects could lend to the radically extended life the sort of cohesion that more ephemeral projects lend to current lives. Indefinite life extension, far from burdening people with a choice between boredom and a disjointed existence, could represent a great opportunity for those willing to embrace this new way of thinking about their lives and what they can reasonably hope to achieve within them.
'Ethical Issues in Human Enhancement' by Nick Bostrom & Rebecca Roache
https://www.nickbostrom.com/ethics/human-enhancement.pdf