I've noticed that whenever I stumble across a person who is stuck in themselves (that is, easily predictable, repetitive, etc.) that there are two primary ways in which they seem to be stuck, and it has to do with whether they are a judger or a perceiver. (I hate the terms rational -irrational. Very undescriptive.)
Judgers get stuck in their judgements, pretty straightforward. They think they know, which can be amusing to watch, but very boring and repetitive after a while.
Perceivers get stuck in their self-identity. It's hard for a J to get a P stuck this way out of their rut. Whenever you try to challenge their identity they usually take it as a personal attack and turn it around on you. They cannot seem to escape themselves.
Anyone else notice this?