Since we have no actual way of measuring how much data the human brain stores (measured in bytes), or how many megabytes it takes to store our childhood, that doesn't really work as an argument.
1) It could be that to format the space required for the 80Gb of inorganically formatted memory, DOES require a lot more space than an equivalent organically formatted memory would.
2) Again, the formatting of the brain to accept data is quite possibly temporary and breaks down a lot more quickly, taking a lot of associated neurons with it.