The manager doesn’t get her job performance review from the barista in the lobby.
The department head wouldn’t ask his next-door neighbor to go over his projections for the fiscal year.
The coach isn’t looking into the stands for insight to fix his team’s struggles.
The manager, the department head, and the coach turn to those who understand the field, the context, and the complex variables to give them necessary feedback. The barista, the neighbor, and the fans are all knowledgable about something—just not about all that matters to these people in these circumstances.
If you’re going to give a speech or presentation, don’t just ask for feedback from the person nearby who has time to watch you practice. Your spouse, boss, and best friend are knowledgable, but unless they are specifically knowledgable about public speaking, their well-meaning feedback can do more harm than good.
What can I improve?
Where are things going well?
What am I not seeing?
Deep and specific knowledge is what allows an expert—in whatever field–to offer truly valuable responses to these questions.