Since my memory is going, I have looked into this stuff. I am DEFINITELY not an expert, but the little I know follows...
The hippocampus is responsible for both processing incoming information AND, more importantly, storing repetitive actions - ever drive home from somewhere and you get home and surprised yourself that you're home? These repetitive actions are stored there, which makes sense in that the brain can devote cognitive issues while doing the repetitive things w/o involving cognitive thought.
Memories are "weight-dependent". That is, if you experience an event or absorb a fact once, it may not stick b/z the brain biochemically assigns a weight to that item. If you experience an event that may have occurred only once, but that touched you (for example) emotionally in some way, that memory may be afforded more weight, since you were able to associate it w/ another event or "meme".
The system is more or less biofeedback, in the sense that may have likely forgotten your high-school sweetheart's phone # (I haven't - I miss her!) since you simply don't use it anymore, hence the biochemical weight (in terms of connections made via neurotransmitter pathways) is reduced.
Memory storage is extraordinarily decentralized. Look at fMRI research done lately and you'll see what I mean. The brain continuously befuddles scientists, since the areas one would term "associated" are far away from one another. For example - your "mind's eye" type visual conceptualization is at the upper back of your skull (right where most bald spots are), far from the visual cortex. Two completely separate areas (Broca's area and Wernike's area) are used for language processing and occur on BOTH sides of the corpus callosum (the conduit b/t the 2 halves of the brain). Yet when one looks at fMRIs for where verbs, adjectives, nouns, etc. are stored all over the freakin' place.
Recently, the G_d part of the brain (associated w/ faith, "divine visions", etc.) has been found and very specifically localized about 2 inches behind your forehead, sitting on top of something called the sella turcica or the turkish saddle - a shelf where, if you look a side image of the brain, the large front part sits upon.
Such a curious set of mysteries, you bring up a neat topic!