An optimist will tell you the glass is half-full; the pessimist, half-empty; and the engineer will tell you the glass is twice the size it needs to be.
But the nearer the dawn the darker the night, And by going wrong all things come right. Things have been mended that were worse, and the the worse, the nearer they are to mend.
History demonstrates that participants in financial markets are susceptible to waves of optimism. Excessive optimism shows the seeds of its own reversal in the form of imbalances that tend to grow over time.
Optimism is a good characteristic, but if carried to an excess, it becomes foolishness. We are prone to speak of the resources of this country as inexhaustible; this is not so.