This article is dedicated to the question: may the subject who uses an artificial device for storing information and consulting it literally know the information contained in this device and got by the subject by way of consulting it? Some philosophers claim the thesis of extended mid, i.e. they consider human mind as a system some parts of which may be external to human body. From this point of view the subject may know the information which is stored not in his memory, but in some computer implanted in him or even in some external storage. The author does not agree with this thesis and think that we don't have sufficient reasons for its statement. But the hypothesis that someone may know what is stored outside of his memory might seem more justified if it could be shown that at least a system consisting from human brain and computer could have the same knowledge as that which corresponding human being would have. Unlike systems consisting from human beings and some external storages working as substitutes of human memory, systems with human brains is based on the same biological processes which provide the work of normal human memory. Can such system have normal human knowledge? The author critically analyzes this hypothesis and shows that we don't have sufficient reasons to answer this question positively. © 2019 RAS Institute of Philosophy. All rights reserved.