We tend to think that if we think or perceive a certain way, everybody must think or feel the same. In some cases this might be true. But there as many different ways of thinking and perceiving as there are people.
Sometimes we think we have an understanding only to discover later that we completely misread the situation.
This is compounded by other factors. People do not always remember things in the same way. Or their perceptions change. You can have the same conversation with the same person at two different points in time and be confounded by the seeming contradictions. We tend to think that, once something is said, it's carved in stone. It's not. As is the case with many things, assumption is the enemy of successful relationships.
For this reason, good communication with your customers, suppliers and employees is vital. The most important thing about being a good communicator is that listening is more important than talking. Being able to hear the other person is essential. And you cannot hear the other person if you are talking.
I once read a science fiction story about a device that could allow an individual to enter the mind of another and look around like you were looking around in their house. It required great trust and most of the users ended up loosing their minds! But I thought this would be a great thing to be able to do when discussing something like the price of a job. And the idea of someone being able to fully understand what you are trying to get across would be a great advantage and save a lot of time.
But such a device doesn’t exists. We are stuck with the need to communicate with words and gestures and deeds. If we want to understand how a customer thinks, we are going to have to work at it.