All very true. The one thing that worn on me about NYC: most people leave after 5-7 years. If you stay longer than that, everyone you built relationships with early on will be gone and the ones from the middle will be planning their departure. You can keep meeting new people to fill up the leaky boat, but gradually as you get older, you lose access to the spaces where all these new, exciting (mostly young) people meet each other.
I love it for so many reasons, but that one aspect does wear on me.