But why stick around to torment your parents? If you want to prove you’re “better” than them, leave and make your own way in the world. If you resent being dependent on them, go out and prove you can do it.
Nick seems to be permanently stuck in a very juvenile mindset, like he never developed mentally past his teens. And sticking around only to keep getting on someone's nerves is exactly what angry, angsty teen would do. Tbh that anger against his parents he had also seems to me very teenagey.