Answer:
Because this type of event creates very strong marks on the brain, creating an emotional memory in relation to the people who were present at these events.
Step-by-step explanation:
Events that promote intense emotions, such as a lot of happiness or a lot of fear, promote deep marks in the brain. These events are never forgotten and it causes a type of emotional memory that makes all the elements present in these events very clear, which makes the individual feel an attachment to all of them, especially the people who participated in this event, going through the same situation or just following along.