Nietzsche is saying to the realists then that it's impossible to extract from our current awareness the sedimentations accumulated over millennia of previous animal as well as cultural experience.

Contextual information that is typically used for filtering includes current date, time, last actions performed, current navigational position, and awareness of other persons online.

Some therapists insist on awareness of both current and desired behaviors, but research suggests it's sufficient to be aware of just the new one.