We each carry a whole world inside our head, apparently, which sounds like it might give you a sore neck, but I don't think my head is big enough, despite what anyone says. The most I could manage would probably be a micronation.
Micronations - in Hollywood they call this a segue - are small self-proclaimed entities claiming to be independent sovereign states, but acknowledged as such by almost nobody else. As a result, they can't have a team in the World Cup (like Scotland in recent times, I'm sorry to say) or take a seat at the United Nations, or even send a singer to Eurovision, which at least might provide some consolation for not appearing on many maps.
Reasons for the creation of such states include social experimentation, personal entertainment, and the conduct of criminal activity. Guns from places like Transnistria have turned up in conflicts all over the world. Existing countries hesitate to recognise new states, lest they be accused of behaving like colonial powers, and neighbouring countries often don't want new ports springing up to challenge their own coastal dominance.
Not that Italy's Republic of Rose Island represented much of a threat, situated as it was on an offshore platform. It sank without trace when the Italian government blew it up in 1969. As did New Atlantis, a floating barge/sovereign republic founded in Jamaica by Ernest Hemingway's brother Leicester. He was some sort of writer, Leicester, I mean.
Many micronations sound tongue-in-cheek, or bite your tongue to stop yourself laughing. The Aerican Empire in Canada lays claim to 'various interplanetary territories,' and with its motto, "The world is ridiculous; let's keep it that way," it certainly gets my vote. But where would the polling stations be? Indonesia's Sunda Empire is even less specific, being located somewhere 'between the earth and the sun.' Perhaps that's why its leading figures were arrested for fraud.
The Glacier republic is in Chile, where else? And no one is sure any more where the Other World Kingdom got to, when it departed the Czech Republic. At least the Kingdom of Wallachia was created as "an elaborate practical joke," like many other kingdoms, some might say.
There is a micronation in Australia on a farm, and -- even smaller! -- the Austrian Republic of Kugelmugel is located in a Viennese park in a ball-shaped house. The Kingdom of Redonda is on the tiny uninhabited Caribbean island of the same name. Good luck being the monarch of that kingdom.
London is a leader in lunacy, as usual. The Empire of Austenasia comprises 24 properties under the leadership of a house in Outer London. (Or outer space, perhaps.) The total population numbers 105 people and English is the lingua franca, if that makes sense, although 'some Latin is used.' An Englishman's home is his micronation.
But beating them all, in my opinion, was the Nation of Celestial Space, comprising "the entirety of the universe." Based in Illinois. I wrote applying for a passport, but was informed I didn't need one. Which made perfect sense, really. Didn't it?