Another meaning which the plateau may have is simply to mark places of greater difficulty. As already remarked, the early period is a stage of comparative ease, but as the work becomes more difficult, progress is slower. It is also quite likely that the plateau may indicate that some of the factors operative at the start are operative no longer. Thus, although the learning was rapid at the beginning because the material learned at that time was easy, the plateau may come because the things to be learned have become difficult. Or, whereas the beginning was attacked with considerable interest, the plateau may mean that the interest is dying down, and that less effort is being exerted. If these theories are the true explanation of the plateau, we see that it is not to be regarded as a time of reduction in learning, to be contemplated with despair. The appropriate attitude may be one of resignation, with the determination to make it as slightly disturbing as possible. But though the reasons just described may have something to do with the production of the plateau, as yet we have no evidence that the plateau cannot be dispensed with. It is practically certain that the plateau is not caused entirely by necessity for rest or unconscious learning. It frequently is due, we must regretfully admit, to poor early preparation. If at the beginning of a period of learning an insecure foundation is laid, it cannot be expected to support the burden of more difficult subject-matter. We have enumerated a number of the explanations that have been advanced to account for the plateau, and have seen that it may have several causes, among which are necessity for rest, increased difficulty of subject-matter, loss of interest and insufficient preparation. In trying to eliminate the plateau, our remedy should be adapted to the cause. In recognition of the fact that learning proceeds irregularly, we see that it is rational to expect the amount of effort to be exerted throughout a period of learning, to vary. It will vary partly with the difficulty of subject-matter and partly with fluctuations in bodily and mental efficiency which are bound to occur from day to day. Since this irregularity is bound to occur, you may well make your effort vary from one extreme to the other. At times, perhaps your most profitable move may be to take a complete vacation. The vacation might cover several weeks, a week-end, or if the plateau is merely a low period in the day's work, then ten minutes may suffice for a vacation. As an adjunct to such rest periods, some form of recreation should usually be planned, for the essential thing is to permit the mind to rest from the tiresome activity.