People who administer information technology (IT Admins, System Operators, Database admins, Security admins etc.) know from experience that most questions that they have to answer every day, and ones they have answered before.
Every IT expert keeps their own notes on how they solve issues. And possibly one of the warmest feelings the average IT admin ever feels, is that knowledge that once they leave a company, their true worth will be understood, when the "new guy" has to try and reengineer all the processes that we're not completely documented.
Modern IT departments use service desks to ensure that all of the processes they are defined are available to all their technicians, and that in the event that someone leaves, all the knowledge that they have created while working for the business is available to new staff.
The knowledgebase function of ticketing systems can dramatically simplify the process of capturing documents and make it available to all IT staff. This can also allow for best practices to be shared and optimized. As systems grow, and change with time, it's important to make sure that every time a process is deployed, and is found to require modifications, that these modifications are saved for future use.