My DB was the golden child.
It has not done him any favors in life at all.
I have a happier sorry than many here though, as my parents have eventually faced up to their favoritism and have put in a lot of effort to have a proper relationship with me now, as an adult.
My mum was diagnosed with cancer a couple of years ago, and my brothers response and subsequent behaviour was in such stark contrast to my own, the scales were practically forced from their eyes.
The downside to this is that my DB (who I was previously very close to, despite his being not very nice to me a lot of the time) now has very little to do with me. He blames me for 'brainwashing' our parents. I did ask him how he thought I pulled that off, was it tapes, hidden messages........ Because if he had any pointers, world domination would surely only be moments away! Lol
So there is hope, and I am very very grateful to have such a much more healthy relationship with my parents and the subsequent peace it has brought to my life. It has also allowed me to let go of a lot of the pain from my childhood and my sense of self worth definitely improved.