Just like currency. All of those were imaginary since they were invented. People have create physical representations for currency in particular, but that doesn't change the fact that it's only a group of people agreeing on something that only exist on their heads.
Equally imaginary things are "corporations", "governments", "military"... If you push hard enough, even "person" fits that, but this one is deeply entrenched in people's minds.
Just like currency. All of those were imaginary since they were invented. People have create physical representations for currency in particular, but that doesn't change the fact that it's only a group of people agreeing on something that only exist on their heads.
Equally imaginary things are "corporations", "governments", "military"... If you push hard enough, even "person" fits that, but this one is deeply entrenched in people's minds.