Is my impostor syndrome actually about isolation more than inadequacy?

Most of it, yes. Kris Kluver, in The Dysfunctional Family Office, asks this question directly. Impostor syndrome is rarely about actual inadequacy. It's almost always about isolation. The feeling shrinks dramatically the moment you discover other capable leaders are feeling exactly the same way. Most leaders never have that conversation. They assume everyone else has it figured out. They keep the impostor feeling private because admitting it feels like proof of the inadequacy they're worried about. The cycle compounds. The fix is to put yourself in conversation with other leaders who will be honest about feeling the same thing. A Peer Circle. A coach who has been through it. A specific friend in a similar seat. The first time you hear another high-functioning leader describe their impostor syndrome out loud, the grip the feeling has on you usually loosens by half. The work isn't to eliminate the feeling. It's to stop being alone with it.