...and the universe will still end one day, meaning the outcome is, ultimately, identical. Why is this so difficult to understand?

I was about to write an impolite response. Let's just keep it at: Your thought is not that deep that it is original or something other people do not understand. You miss the point where your Existenzangst is applicable and where it is not. Jumping on meta-levels and missing that we talk about the time period where consequences matter - like for how much fun there is when you play the game during the period our universe actually exists - is not profound. Looks like a bored effort to derail the discussion to me.

Simple question: how much did the ending actually matter to your enjoyment of the game? Would you have ignored the game and simply watched your preferred ending on youtube? Would you have told your past self not to play the game at all given how the ending actually is?

These philosophical questions are not as separate from the day to day reality as you want to believe.

It compeletely destroyed every bit of enjoyment I took from playing and finishing the game. Yes, I would have not played the game and actually do that regularly when it comes up, to tell people to not play (and to not buy!) ME3. It was that bad.

> It compeletely destroyed every bit of enjoyment I took from playing and finishing the game.

So... you didn't enjoy anything at all up to that point? Really? Then why bother playing it at all? Why not let someone else play it and just watch your preferred ending cutscene on youtube? Is it really all just about the destination and the journey means nothing?

You know that this is not proven right? Or rather, not even a "theory" in the physics sense, there are multiple competing hipothesis, none of them have enough evidence for us to be certain the universe will end... In some ideas the university does end, but in big crunch, or big rip, in others it just starts anew, in others humans spawn new universes, and so on...

None of the popular options sound like your choices will matter a lot in the end:

https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe

There are a lot of competing theories of how the universe will end, but pretty much all mainstream cosmology admits that it will end. Very few cosmological models say otherwise.

However, even then I contend that eternity is just another kind of ending. Given an infinite time, everything that can happen will, and therefore it will also repeat. That means that every decision we make will be made again infinitely, every path followed an infinite number of times, always eventually returning back around again, and ultimately the outcome will still be the same.

So you see, under cosmologies of eternity, we just exist in a stasis of infinity and our decisions will not change that. Under cosmologies where the universe ends our decisions will not change that either. Does this mean that nothing we do matters?

"but pretty much all mainstream cosmology admits that it will end."

By using "admits" you mean they accept your point of view, even if they do not want to? Thats a bit telling about your worldview.

And have you ever considered, that cosmology can only make relative observations and speculations?

In other words, if our whole universe is just a small part of a bigger universe, how could we tell for sure, if all we can observe is within those borders?

Also, how likely is it, that out of eternal nothing someday came a whole universe which wents back to nothing forever?

Sounds more like religion than science.

> By using "admits" ...

"admits" can also be used to mean "accepts as valid"

I know. But in this context it did sound like the other explanation to me. (Probably not aware by you at the time of writing it)