Why might an ENFJ display introverted characteristics, and how can you tell if it's a temporary phase or their actual type?

Is being picky about certain preferences, like wanting a steak cooked a specific way, common as people get older, or is it more about individual personality?
What happens when you stand up to someone in public, especially if they're in a position of authority? How do you handle the potential consequences?
Why do some people believe thoughts come from emotions, while others think they're separate from our brain? What's the big debate here?