Especially those who do not imbibe on any regular base, intoxication can be difficult. We may even make some terrible blunders and error judgements. For certain we do not drive automobiles. We might even get sick. Yet the Rabbis, being of good mind and spirit, saw that this state can be beneficial to a person's spiritual and emotional development.
Most people base their happiness on their successes.
If they succeed, then they are happy. If they fail, they fall into a brooding that can border on depression, if not becoming an actual depression. Because they consider the outcome of their striving to be an extension of their person, of their egos. The opposite may truly be the case. A truly happy person is a person who realizes that his successes are not dependent upon his strivings.