We speak of adventure precisely when continuity with life is thus disregarded on principle—or rather when there is not even any need to disregard it, because we know from the beginning that we have to do with something alien, untouchable, out of the ordinary. The adventure lacks that reciprocal interpenetration with adjacent parts of life which constitutes life-as-a-whole. It is like an island in life which determines its beginning and end according to its own formative powers and not—like the part of a continent—also according to those of adjacent territories.

Georg Simmel, on individuality and social…, loc. 466