Realistic Life in NYC?

I know everyone says NYC is crazy expensive to live in and whatnot, how true is that? I've always wanted to eventually move to NYC, but I don't really have any real idea or concept of what it's like to live there outside of stereotypes or jokes online. Is it crazy expensive to move there? How hard is it to find a job? Is it difficult to find an apartment? I work in EMS and would stay in that field, if anyone has any insight as to what the field of EMS is like in NYC. So basically, is it unrealistic to want to move to NYC if I'm not already super rich or well off?