Though closely associated with Russia, both before and after the 1917 Revolution, the concept of “internal exile” is not exclusively linked to the Soviet experience and has existed at other times and places. But internal exile during the Soviet period came to mean far more than a definition of where you could and couldn’t travel. Instead, it represented something more metaphorical—about traveling within yourself or relocating mentally. It signified a sort of “retreat into the self” that allowed many people to live more happily while avoiding anything to do with politics or public life. 
Source : A Refuge from Reality, à la Russe
