If I remember correctly apparat from the injuries O’Brian was also hit by the homesickness bug.
In the last 15 years with zoom and social media etc the world has shrunk even more. Yet even now coming to the North of England in the middle of winter is still a shock and I totally get that having experienced it.
Why it affects Aussies more than people of Somoan or Tongan decent I don’t know, but it does. You’d actually think it would be the other way around though I suspect it’s there support networks that help them through the transition.
I have full sympathy and it happens both ways, the majority of English players in the NRL return home at some point.
So it’s not just age or injuries, it’s deeper than that, you basically either like it here or you don’t. If you do you will probably do well even at 34.