This 2014 primate study provided evidence that our memories are formed within a specific context:
“The hippocampus, a structure known to be essential to form episodic memories, possesses neurons that explicitly mark moments in time.
We add a previously unidentified finding to this work by showing that individual primate hippocampal neurons not only track time, but do so only when specific contextual information (e.g., object identity/location) is cued.”
As the study may apply to humans, it would follow that accessing a memory’s specific context would be a necessary part of accessing a full memory.
http://www.pnas.org/content/111/51/18351.full “Context-dependent incremental timing cells in the primate hippocampus”