My sister was the golden child of both our parents, for different reasons. I know this because, despite being a very 'good' girl (clever, musical, lively), by my mid teens I had to face the truth that nothing I did was ever good enough for either of my parents. Asked them who their favourite was, &, independently of each other, both told me my sister.
As an adult I've struggled massively with confidence in all areas of my life; took til my 40s, and lots of therapy, to start to overcome depression & start to gain some confidence. I'm poor though, and struggle financially, as sadly have been unable to sustain a career. By contrast my sister has always been very confident and is now successful, popular and wealthy.
In our 20s I tried to discuss her GC status with her, and the positive effects this has had on her(and negative effects on me of being the unloved/unwanted child). She refused to acknowledge her GC status; complete denial of my point of view. For her, being GC was the 'norm'; she accepted our parents' view that I was the 'difficult' one (I really wasn't!) and believed wholeheartedly that she deserved her favoured position. She simply doesn't see that our parents were unfair in their unequal treatment of us and has always been happy to believe she deserves all the advantages she's had in our family because she believes that she is, somehow, more worthy. Strangely though she's not happy with my increased self confidence as I've got older, so maybe being the GC isn't everything?
As adults I've had to go low vlc with her, sadly. Her attitudes towards me seem to continue the damaging attitudes our parents had towards me, and I've had enough of living with these painful distortions.