when i was reading the carlos castanedas books i didnt really understand what don juan was talking about . in studying magick i have noticed some things.
Body Memory-
the body remembers how to do things. to me this represents many things for instance psychic exposure and possibly past life memories of abilities that are latent now.
psychic exposure from my experience works like this. unconscious memory and conscious memory. unconscious memory can be unlocked by meditation and contemplation. recapitulation can be used here.
for instance memorizations of various energies

as for past life memory there is also unconscious and conscious. these memories come out by also meditation and contemplation.
and sometimes hallucinagenics open those memories as well. my knowledge is limited in past life memories since i dont know if i believe in it yet. only times i have remembered anything or seen anything was in random flashes.
for instance i have had hawk vision where my vision locks on a n object and i see up close like a telescope.