> Know what people are asking you to be an expert in

I read this as “leave it to the experts and please realise that sometime it’s not you” which is something that is sometimes quite hard for micromanaging delivery leads or business stakeholders when it comes to implementation details. Worst is when there are endless progress update meetings about some some irrelevant detail that then holds up the whole project.

Similarly it is quite difficult for developers to realise that leaving design decisions to user researchers and ux designers is a good thing!