As the term implies they were the best performing students from each course
Except that often they weren't! Certainly in the late 90s, the Golden Balls guys would often go straight through training, because they were clearly single seat material, whereas solid but unremarkable guys were sometimes chosen to be creamies to give them a better chance of a Harrier/Jaguar slot when they subsequently went through Tac Weapons.
In my experience though as they had generally passed through their own training with relative ease they weren't particularly understanding of those that found it hard.
Agreed.