Welcome to London, Europe's biggest metropolis.
1. London is much richer.
This measures roughly how much economic output each region of England creates per person. Though it makes up just 13% of the population, London accounts for 22% of the British economy. Londoners earn, on average, 29% more than in the rest of Britain.
2. Londoners come from everywhere.
37% of the capital's population was born abroad, compared to just 9% of the population outside of London.
3. Which means that they speak all sorts of languages.
4. And London is far less white than the rest of Britain.
In fact, less than half of the population identify as "white British", the majority group nearly everywhere else in Britain.
5. Londoners are much better qualified.
The capital draws graduates from all over the world, but also from the rest of Britain. Over a third of new graduates move to London when they finish their degrees.
6. And much younger.
Of course, this varies depending on where you are in London. In the inner city boroughs of Tower Hamlets and Newham - first ports of call for hipsters and immigrants just arriving in the city, the average age is just 29. In suburban Havering or Bromley, it is closer to the national average at 40.
7. London is the only region where more people rent than own their own homes.
In 2011, 49% of Londoners said that they rented their home - about half from social landlords (such as councils) and half privately. That's probably because the average house price in London is more than twice what it is elsewhere in Britain.
8. And the only place where most people live in flats.
Tiny tiny flats that cost ever so much money. According to one calculation, the property in just ten London boroughs is worth more than all of the property in Scotland, Wales and Northern Ireland added together.
9. It is also the only part of Britain where more people get to work by public transport than drive.
10. In terms of what they get up to, Londoners are more likely to use drugs.
This is probably mostly explained by Londoners being younger, since young people use more drugs. People in the capital are particularly keen on cocaine. 3.5% of Londoners aged 16 to 59 have taken it in the past year, against just 2.5% in England generally.
11. But curiously, they actually drink less.
12. Unsurprisingly, they like poncey food more.
13. Although it probably depends on who you are. London is far less equal than everywhere else in Britain.
So why does this all matter?
The trouble is, quite probably both are true.
So that's why London will always be unique.
For all that people worry about the malign influence of London – or alternatively, suggest that the city should be independent - the rest of the country wouldn't be the same without it. London may feel like another country, but it matters to everyone in Britain. So don't wall up the M25 just yet.