Is immortality a road to nowhere?

An unending life would be one that lacked any meaningful shape or pattern. It would resemble an infinitely long river that meandered eternally without ever reaching the sea. There would be no arch-shaped structure of birth, growth, maturity, decline and death. Although phases of the life might have their own internal structure, it would be as a whole (not that it could ever be grasped that way) completely shapeless. It would be a life that was going nowhere specific, and in which the people, projects, and aspirations that were important at one stage would be insignificant and forgotten at another. Geoffrey Scarre, Death (Routledge 2014).

i) To play along with his metaphor, boating down an infinitely long river means we'd never see the same scene twice. The scene would constantly change. And that would indeed be maddening.

But why suppose unending life must be analogous to that? Why can't eternal life combine variety with repeatable experiences? 

ii) Scarre fails to distinguish between temporal ends and teleological ends, yet something that's endless can still be patterned. The Mandelbrot set is infinite, yet highly structured. 

Finnegans Wake has a circular plot. It has no real beginning or ending. In principle, you can open the book at any point and start reading. You can break into the circle anywhere. Once inside the plot, repeated reading will deepen your understanding of the plot. Things you initially miss you will appreciate after going around a few more times. Of course, that could still become tedious, but we're just toying with metaphors. 

Take the common experience of leaving home and returning home. That's repetitious and circular, yet it doesn't mean you're going nowhere. Moreover, leaving home enriches the experience of returning home. 

Furthermore, if we lived forever we would need to be equipped with vastly more powerful memories than we have now to be able to recall our own distant pasts. McMahan might contend that it would not be important to be able to remember our origins or ancient history so long as we could remember our more recent past (say, the last century or so). But if we retained anything like our present psychology, we would feel ourselves deeply alienated from our own pasts if we had to consult the history books to learn about our former deeds. (Also think what an unsatisfactory sense of self one would have if one could no longer remember one's childhood or one's parents.) We care about what will happen to us in the future, and what happened to us in the past, because we see our past and our future as parts of one and the same life, chapters in the same narrative. No coherent, graspable narrative, however, could link together our existence over endless ages. Fischer has suggested that while an infinitely long life would not have "narrative structure, strictly conceived", the "literary analogue for such a life is not the novel, but perhaps a collection of short stories…with the same character appearing as the protagonist" 

That objection seems to be based on immortality in the sense of never dying, rather than a Christian model, where there's distinct phases: life before you die, the intermediate state, and the final state. His objection involves an undifferentiated continuum. But on a Christian model, I don't think it would require a vastly more powerful memory to recall your life before you died. 

And do we actually need a vastly more powerful memory to recollect what happens to us if we just keep on living? That's never been put to the test. Memory is already highly selective.