There were a couple of points I keep thinking about:
SPOILER ALERT
1) Where they are navigating broken ice on a heaving ocean and Shackelton casually mentions that he hadn't slept for over 100 hours as he was trying to pick a safe route through the ice (I expect people would argue that is highly likely to kill/drive you insane).
2) Where a wave breaks on top of their small boat that is so high that they can't hear it yet and Shackelton initially thinks the white crest way above them is actually a break in the sky indicating clearing weather.
And I have a sore neck because my keyboard/monitor arrangement isn't optimized.
A memorable element was the mens’ reaction to WW1. Them asking “who won?” felt awfully like one would ask about a football game.
But I found Ernest endlessly describing every depth measurement and the stomach contents of every penguin they killed hard to get through.