Yes, specialisation over decades. Perhaps almost as important: I started in the US, and still work almost exclusively for US clients. In a world where I can wo

Yes, specialisation over decades. Perhaps almost as important: I started in the US, and still work almost exclusively for US clients. In a world where I can work almost as easily 12 time zones away as 2, I'm not sure why these huge continental disparities still exist, but they do.