Indicates a high level of proficiency or familiarity with a task or place.

Expression of Skill

It is used as a way of speaking figuratively, not to be taken literally.

Figurative Speech

It’s often not about a physical action, but about doing something familiar or routine.

Implies someone is not paying attention to their surroundings or situation.

Highlights that details or important elements might be missed or ignored.

The phrase can metaphorically signify one’s ignorance or intentional overlooking of facts.