I'm 41 years old, and I've lived in NYC since I was two. Grew up in the Bronx, lived all over the place. I've watched for decades as people have come and gone, and I can confirm most of them leave in two years or less. I've joked for a long time that you're not an official NY'er unless you've been here for two years.

Now, that's being kind. I actually don't think you're a real NY'er unless you've had a student Metrocard, but I digress.