Once upon a time there was a group of primitive people.
And every day they would fight, not only to survive but with each other for shelter too.
Until one day they learned how to make tools.
And because of this they were also able to make weapons for hunting.
And because of this they were able to use animal skins to make shelter and not worry about finding caves and other natural shelters.
Until finally they had enough shelters for everyone.
And ever since that day they’ve been traveling with the animals and living off the land.