What in the world am i talking about? I'm talking about the fact that i were there for 3 weeks the last time - lived in Brooklyn, and almost 100% of the times i took the metro downtown there were extremely unstable and mentally unwell people in each train, and often even in multiple wagons just walking around talking to people / the air / pissing themselves etc.

Absolutely nowhere in Europe will you experience that with that frequency yet, even though it's getting worse. Rough areas? Many. The weird guy here and there in the Subway, off course - but almost each and every time you drive in the subway - hard no! I lived in london for a few years and never really encountered any totally strung out people with their pants down, i did multiple times in NY in those 3 weeks.

Also off course i'm not talking about Williamsburg, a good example was going just north of the richest areas in Upper East side into Harlem, and wow what a contrast.