What is something most people don't know about New York?

One: It's more than just Manhattan and skyscrapers.

Manhattan is unquestionably the political and economic core of the city, but there are four other boroughs, none of them as “built up.”

Two: because all subways lead to Manhattan, a lot of people in the Outer Boroughs (read: not Manhattan) may not have a ton of experience in the other boroughs.

For example, from where I used to live in the Bronx (around the 1 and 4 Lines), it would be an ordeal to get into Queens or Brooklyn -- I'd have to go deep into Manhattan and then transfer. So I've rarely gone there. My mom compared Queens to “the edge of the world".

Much easier to just meet people in the middle -- Manhattan. Which I'm sure Manhattan businesses just love.

There's always been ideas to connect the Outer Boroughs directly by rail, but such plans never go anywhere. Manhattan has a (imo) kind of imperial relationship with the other boroughs. All roads must lead to Rome, after all.

The idea that never becomes reality

Three: Staten Island.

It's weird.

But as a Bronxite, I am thankful for their existence. They are the one borough that gets shit on more than the Bronx.

EDIT: I'm aware this is a very NYC-centric answer. Alas, I've not experienced upstate NY very much. Don't have much to offer on that end.