To dream of an anniversary can symbolize various things depending on the type of anniversary and the context of the dream. Dreaming of a wedding or relationship anniversary is representative of love, commitment and fidelity.

Forgetting your anniversary in your dream indicates that you are
experiencing anxiety within your relationship or that there is currently animosity between yourself and your significant other.

A birthday symbolizes the passage of time as well as achievement and hope for the future, while the anniversary of a death symbolizes remembrance, commemoration and respect.