Think about what just happened. Without much provocation on your part, your student volunteered volumes about what's happening inside his head. He's under some pressure to meet his work obligations. If his learning progress diminishes unexpectedly, you have a clue where to start looking for the explanation.
Suppose during ordinary conversation your new primary student says that she hopes learning to fly will help her relationship with her pilot husband. She adds that without some flying skills, she feels she won't be able to share his passion for flight. Bingo! By listening carefully, you've acquired a great deal of useful information. Your student's motivation for flying is only indirectly associated with the pleasures of flying itself. Her main motivation is connecting with her husband and his passion for flight. With this information, you now have a much better idea how to teach her.
While individuals may not tell you all about themselves during normal conversation, they often tell you enough. Listen carefully to the things your students say, and you'll have a much better idea about how, and what, to teach them.