It's wrong not to think about others personal space.
Kevin works at a fast food restaurant that delivers food to its customers and an order is up to be delivered.
Kevin wants to give the food to the customer.
Kevin places the food on the table, extends his arm, and hands the customer his receipt.
Kevin places the food on the customer's table, comes shoulder-to-shoulder to him, and shows him the bill.
The customer gladly takes the receipt and thanks Kevin for the food, feeling comfortable the whole time.
The customer gets uncomfortable and tells Kevin to back off or else.