Nowadays it is often not enough to be an expert in your own field of business. It helps to apply a little psychology to your business dealings. Look at this picture. What about this.
Different people give different answers to the questions on the left.
Some people says there are two small squares and a larger one, others say there are three squares. In the final picture, some people see an old woman, others see a young one. It confirms that we all have different perceptions. Our perceptions affect our expectations and attitudes in life in general and in our business dealings. Our attitudes and our perceptions of other people affect our relationships with them.