Traditionally everyone thinks of a store employee when they think of customer service. With IT, everyone is a customer, from the internal end user, an external client or others in IT. Some users are not technical, or their specialty is in IT, but not the same as others. They may only know how to use an application in a specific way and possibly be resistant to learning other ways because of fear (false evidence appearing real). IT roles often need to be the multi-tool in a business, you may not be 'an expert' in any specific field, but know enough about others to assist or even direct them to a specialist they need. During this you may also learn more about the subject yourself and extra insight into the business and challenges users experience. Also, if you teach someone how to do something themselves, they may not need to reach out to IT again, empower users and other staff to work more efficiently, but leave you open to have time to learn more yourself or work on other projects.