The setting in which a thing is found or occurs is extremely important for the associations  that are so crucial to memory. The physical & cultural context in which the learner learns a thing can also be helpful in building an associative network for later recall. Everyone has had the experience of going in search of something and forgetting what they were looking for.- then having to return to the exact spot in which the need for the thing was first conceived, and remembering it instantly. The place in which the item was initially moved to long term memory jogged that memory and the item was recalled. Students tested on material in the room where they learned it  tend to do  better on the test than those tested in another room. It seems that the place in which we master information helps recreate the state necessary to retrieve it, probably by stimulating the right emotions, which are very important influences on memory. 

 Memories retained in a given mental or physical state are most easily recalled in that state. People who learn a fact while intoxicated may have a great difficulty remembering it while sober, and it will come to them immediately, almost miraculously, when under the influence again.