The assumption that humans inhabit the physical world and "access" digital space from that base is becoming descriptively inadequate for growing segments of the global population. This paper proposes the Inverted Anchor Hypothesis, which holds that the default locus of daily life is shifting from physical reality to digital space, transforming the physical world from a point of departure into a point of return-a destination requiring conscious effort to reach. Five types of "ground anchors" connecting human cognitive, bodily, and social activity to physical reality are identified: bodily, social-obligatory, intimacy, economic, and intellectual. The paper argues that the cascading severance of these anchors opens a physical pathway to the irreversible loss of cognitive autonomy-a pathway that does not presuppose the arrival of artificial general intelligence and is already partially operative. The Japanese phenomenon of prolonged social withdrawal (hikikomori), with an estimated 1.46 million cases among the working-age population, is examined as a leading indicator of this pathway. The paper further identifies a structural trap: because social withdrawal and AI proliferation are managed as separate risk categories by distinct expert communities, the point at which they intersect-where technological substitutes seamlessly replace the 1 last human infrastructure supporting physical-world connection-remains invisible in both fields.