It's a commonly expressed and rather nice, romantic notion that we are all "sisters" and "brothers."
Let's be real. Fact is, we might be better served to accept that we are all siblings.
Siblings fight, pull each other's hair, steal stuff, and accuse each other indiscriminately.
But siblings also know the undeniable fact that they are the same blood, share the same origins, and are family.
Even when they hate each other.
And that tends to put all things in perspective.