The poster quite possibly was using the cold war definition of "west" (which is likely way more relevant to the comparison they are making), not the antiquity one.
The OP obviously means 'Western Europe' but the way he wrote it, in the context of international readers, doesn't make sense, because it reads as 'Western Nation' (i.e. Europe, N. America, Australia, NZ) In his local context, 'The West' could very well more likely mean W. Europe, no doubt - I'm sure it's crystal clear to him/her. But this is a North American board, with an international readership.
If you say "Developed Western Nation" in this context, for example, in the press, or even on the BBC it means the 'classical west', not 'E/W Europe'.
Australia is located in Asia Pacific, and the US is in North America but they are 'Western Nations' by virtue of their cultural history.
So, growing up in Europe could mean that you grew up in the Balkan countries during one of the wars in the 90's. Also, even if you think that map is wrong, countries in the Balkans are certainly not a part of "developed western nation".
My down-voters are utterly wrong.
'The Western World' is a term derived from antiquity, in which 'the middle east' is at the centre, East would be China etc.
In modern terms, the US, Canada, Australia and New Zealand would be considered Wester nations.