The value of "know your customer" style lines is that they allow people to communicate to each other about things they already know. Those lines are not useful

The value of "know your customer" style lines is that they allow people to communicate to each other about things they already know. Those lines are not useful to anyone who doesn't know them because knowing what "know your customer" really means is the important thing. I encountered the phrase when I was 14 running a managed web hosting company. It didn't help because I didn't know how to know my customer. I wouldn't buy a book like that because I know it would be completely useless since it has no actionable advice for me. That's how it is for me.