I've given some thought to the concept of the Limitless movie. One the one hand, some people are very smart and it seems that there is a physical basis for that, regardless of nurture. But the idea of being able to tap the subconscious has complications. The subconscious is "sub" for a reason. There are psychological and physical constraints that limit our subconscious' ability to just dump all over our ego.
Completely ignoring the physical necessity of blocking memories, one must be psychologically equipped to handle that kind of access. Any such pill would have to include some psychedelic element. Not hallucinations necessarily, but it would have to force a person to think in a radically new way. A person of the right constitution could just choose to think in this way, and perhaps gain some benefit. Memories become inactive in part because they are uncomfortable. A pill which granted unlimited access to such a repository of discomfort would most certainly be overwhelming, in a manner not unlike an lsd trip. If one is supposing that "extra control" over such recall might be possible so as to avoid negative experiences, then we are back to where we started. It is precisely because the ego has such control that memories are suppressed.
If you empower the mind, you empower it to do what it already does. If you suppress it(suppress the act of suppressing), then that person better have exceptional coping skills(other than suppression). It stands to reason that if a person could just increase their emotional coping skills that the lack of need for suppressing memories would lead to greater creativity and naturally better recall.
I think that there is a psychedelic way of thinking, where one strengthens the connection between ego and subconscious and is emotionally prepared to not have negative feelings about any thought that comes to mind. I think just being open minded does this. Many people who are open minded are very close minded about being open minded. That sort of judgemental non-judgemental-ness is yet another incarnation of pride. Pride is opposed to knowledge because it is necessarily narrow. It is this and not that. One should be open minded and not pride oneself on being so. Nor be too harsh on other people's lack of open mindedness.
I had the thought that it might be possible to create subconscious puzzles. The way a name is on the tip of the tongue and then comes to mind at last, or the way you can look at an acronym you have never seen and guess with a spontaneous certainty that you are probably correct.... It may be possible to develop puzzles in which people take a moment to consciously appreciate the "problem" and then endeavor not to consciously solve it. Only to be aware of the problem. Food for thought.