It does not make sense to me why people would want to live beyond 50 years old, especially since health problems start becoming more frequent around that age.
Which makes me ask: Why do people wish to live long beyond the age of 50?
Thats exactly my point about the 'during'. Ultimately the only reason it has any meaning is because as animals for a large part of our evolutionary history if it didnt, we'd go insane and probably wouldnt reach this point where we can type messages to each other over the internet. For all of time before humanity, and for all of time after we are all gone (let alone any single individual), the blip of our existence ultimately doesnt have meaning except for the short blips themselves.
And yes, 40s is partly because thats when the living itself starts to become uncomfortable and/or downright painful, but mainly its just an arbitrary age.
Edit: you said you try to enjoy life as long as possible. Im the same, just sans the "as long as possible" part ;) Its not like I dont like fun or dont have things that bring me enjoyment