How Are Memories Stored and Retrieved?

Answer 1

The reference is a good place to start.

Answer 2

That is not too well understood, but looking at the capacity observed, likely happens on the gene level. ~
Also, being able to correlate memories as efficiently as we can we may be creating electro magnetic holograms that interfere with each other in constructive and destructive fashions to retrieve memories in the most efficient manner.
Somewhat similar to the way plants convert 90% of solar power, via quantum waves playing across the chlorophyll until most of the sun's energy has been captured.
Once we can duplicate these processes in computer chips, we will have an increase in computing capacity that most people consider forever impossible (not me though!).