cut off from the (outside) world
1. Literally, completely separated from people outside of a given group or space. Prison inmates, especially those in solitary confinement, face an extraordinary pressure on their psyche from being cut off from the outside world for so long. The tiny rural village, cut off from the world up in the mountains, developed a dialect and manner totally unique from the rest of the region.
2. Figuratively, isolated from broad and/or meaningful outside engagement or interaction. Their research, while promising, is flawed in that it is cut off from the outside world, so its effects on the greater population are only speculative at best. Art—good art, anyway—is never cut off from the world; it is totally enmeshed in the people and culture around it.