I can't recall when I read it, but I also thoroughly enjoyed it, even though I had no idea what entropy was (and I'm not much wiser now!) but I could grasp all the stars would grow cold and die, and the ending was a great one, and I'm sure would have been an even greater shock at the time it was written.
I've had a quick re-read of it again now, and I'd forgotten that riff about umpteen billion years not being the same as "forever" which struck me as very human and natural, and the children's reaction to the stars going out. Odd, though, that he expects humanity to continue multiplying at such a rate despite increased longevity and good health with that long life. Surprising, also, that aliens are nowhere encountered as humanity spreads throughout the universe, and it's Man's idle questions which create life -- human hubris all over again!
And in answer to your question, dsri -- it's perfectly possibly to discuss the story, as you can see. It's the discussion of religion itself which isn't allowed, because of its propensity to create division, flaming and trolling, none of which are welcome here.