The faded memories extend their weakness over the present state, because the present state has to confess its incapacity of keeping alive those memories.
If the general notions are conceived as outcomes of an accumulation of similar memories, then they should contain the weakness inflicted by the older memories.
Or, we might take the general notions as the results of some decision to cut off the older memories in order to preserve the immediate reference to the memories closer to the present state. Because only an immediate reference gives to general notions the power they need for being accepted as preferable means of discussing the reality.
Accordingly, the user of general notions pretends that he is always able to confirm their sense by a direct appeal to memory.
When it is attributed the understanding of general notions, it is supposed that one can make such a direct appeal to his memory, ignoring the fact that it is an appeal only to the recent memories.
Thus, the misunderstanding of a general notion could be interpreted as a sign that there was realized an appeal to some older, faded memories in the mind of one who would be reckoned as an ignorant man.