Memory, the ability to remember what is dangerous and what is safe, is a basic prerequisite for an individual's survival. In all animals. A deer remembers that a wolf is dangerous, that when it hears gunfire it means danger, it remembers the smells of the beasts that hunt it. That's why it has a chance of survival. It's the same for humans. Thanks to his memory and his ability to avoid known danger, he has survived as a species.