This phrase is used to describe someone who has all the necessary equipment for a task but lacks the knowledge or skills needed to complete it. It is often used to describe someone who is overly confident and ambitious but not prepared for the challenge.
来源：BATMAN UNBURIED EP1 TRANSCRIPT
BRUCE: And what about the lights? Seems like a lot of gear for a psych eval.
HUNTER: My father used to say, “All the gear and no idea.” In fairness, almost everything to do with the brain is a bit of an unknown.
BRUCE: Very reassuring.