A great hope or expectation is not great because of its intensity in our mind. It is great rather because it surpasses the mind and plunges into an imaginative building which imitates the real life.
For this reason, the disappointment felt after our expectations failed is not a problem of our mind, but of our life.
It becomes harder to live further all those facts of life which were imaged in the failed expectation in a positive light. Moreover, those facts were primarily borrowed from the hardness of life in the subtle series which can be conceived only by imagination. Such subtlety cannot be met by simply living.
Therefore, the hope cannot be reversible: we cannot hope and then to stop from doing this and to live as if we did not hope. Our life is changed for ever by our hopes.
And though we know that hopes make our life difficult to live, they are still preserved. Not only because we wait for their fulfillment, but also because the use of a realistic view of life is only a part of our life, even if it might possess the whole truth.