Looking at this through transhumanist metaphors, like in any of dozens of scifi works to cover future cognitions well (my favourite is Eclipse Phase, if you want a recommendation).

Exocortices would be great if the modern technology was there to support it, but the current paradigms make memory-access too slow and unreliable to be worth the agency benefits, especially since current brain formats need internally-stored memories for default-mode idea generation in the background and can't make good use of location pointers for dreams.