If you are walking alone in the wilderness and you come upon another person walking alone in the wilderness, that person could be a deranged killer. You have a choice to make. Do you wait and let them kill you, or do you kill them first? /s This is why I do not walk alone in the wilderness.
There is a quote from some Army/Marine general during the Iraq war. Something like “Be professional, be polite, and have a plan on how to kill everyone you meet.”
Not a bad way to view some everyday circumstances as well.