The core of the traverser will not change in any way, including memories.

The first level, which only changes the memory of the film. Travel through a movie world and revise the plot, and the memories of the first-level people about the movie become modified memories. This level includes loved ones, people in close relationships, friends who know each other very well.

The second level is to change the memory and trace life impact of the film. This level includes distant relatives who basically don't get along, ordinary friends, classmates at all stages, celebrities who know and love very well. It also includes the first level of the traverser level person (a loved one, a person in close relationships, a friend who knows him very well).

The third level, changes the memory of the film and a small amount of life impact. This level includes people who know but are not familiar with it, including celebrities who know a small amount about celebrities.

The fourth level is only guaranteed to appear at the right time in the traverser's memory. This level includes people who are close to each other, passers-by, and people who have met once and only know their names. Photos of people seen online.

The butterfly effect does not necessarily mean that it will affect the people around the traverser, but it is possible. A person who doesn't watch movies at all, most likely, won't be affected in any way. But this influence will increase as the time-traveler changes more films, which is also the meaning of protection.