You can navigate a performance review successfully if you go into it with firm evidence about yourself. Managers spend years trying to master the art of giving a really good performance review. But you have the opportunity to make the process much more fun, stimulating, and enriching for both parties. Your job is to make it as easy as possible for your boss to write you a terrific report. Your boss may have some idea of your accomplishments but may not be keeping close tabs on both processes and results.
Most managers conduct and write up a group of performance reviews at once.
They're working under deadlines set by the department and their boss, and they may not have access to everything their direct reports have done during the year. You have to build the case for yourself. The better prepared you are, the easier it is for your boss. Document your accomplishments. No one is paying closer attention to your work than you are.