Changing opinion is a common phenomenon in human behavior, and there are many synonyms for it. One of the most common is to have a change of heart, indicating a shift in one's emotions or values. Similarly, one could have a change of mind, indicating a shift in one's thoughts or beliefs. Another commonly used synonym is to shift one's perspective, indicating a change in one's understanding or interpretation of a situation. Other synonyms include pivot, transform, evolve, and adjust. All of these words imply a change in one's mindset and can be used interchangeably when discussing changing opinions.