How does memory work

There are 2 main theories on how we remember: those that fire together, wire together and bell theory.

Lets take a scenario. You see a mango, just by looking at that mango, another picture comes in your head, and you see your classmate on a mango branch extending her hand to reach for a ripe green mango. Along with this picture comes the feeling of excitement and giddiness, yes, she can almost reach it! yes! and she got it!!! The interesting thing is how can just one mango link to the picture that you saw in your head. There is a huge difference between the 2 scenes, both temporally and spatially.

the code would most likely be:
mango here, mango in Tanzania, mango from tree, [link?], my friend taking the mango from the tree, she got the mango, i am excited she got the mango.

Whatever the case, there is a similarity between one point and the next. It seems like there is a flow chart of memories.

I come to the conclusion that remembering something depends on a trigger, that will cause the memory to resurface. However, how is it that the nerves are organised that will bring about a complex phenomenon as remembering? Maybe, the wiring of memory is just a simple command that just happens to produce a complex behaviour? if so, what is the simple command??? How can it be beneficial to increase our memory?