Functional anxiety is pervasive and strange

It's subconsciously thinking ahead of every scenario, conversation, reading people, and preparing for extreme scenarios without realising it. It creates a mask or persona that reacts to the world to keep you safe, at the cost of losing your sense of self. Eg. Walking down the street on a sunny day, still scanning for danger.

It's learned from chaos or PTSD in early years and the brain does it automatically. Its constant survival mode. It creates higher stress responses which means you can take less of it, become more exhausted than others, feel drained at large social events due to the brain working overtime in over analysis.

Many people call this introversion, it's likely functioning or general anxiety popularised as a personality trait.

Food for thought