It seems to come down to a definition of what it means for something to be a part of your identity. All of those internal discussions the waiter has, he can hav

It seems to come down to a definition of what it means for something to be a part of your identity. All of those internal discussions the waiter has, he can have those productively, probably more productively, without making waiterism his identity. The point of limiting your identity to the core stuff, like providing for your family, is that those are the things are truly matter. If you can't provide for your family, that will hit you like a ton of bricks, regardless of whether it's part of your identity or not. But if you let a nasty comment about your hairstyle, the viability of socialism or whether Jesus really existed bring you down, you can choose not to care because it doesn't really matter (in that isolated interaction, the questions may well matter in the grand scheme of things). Also, nobody said this was supposed to be easy, something you just flip on and off. But it's something individuals can think about for themselves and decide whether their haircut or profession is really important enough to feel attacked if someone makes a nasty comment.