[jerf]

'Just consider, if a person actually a video tape of their entire life, using said tape to answer questions about "what happen on day X" would take a few hours of mental processing.'

You're making a huge pile of unsupported assertions, but this is the most egregious. You have the outline of an interesting theory, but little more. For one thing I see no evidence that there is any conscious effort made to maintain these memories, in many cases the people express every desire not to have this happen, yet it happens anyhow. At the point where your "making themselves experts" happens at a purely automatic level and against their conscious will you've stretched the words beyond any reasonable meaning, and I'm not sure your theory can even in principle be converted into something that corresponds to the real world.