In the context of the passage, what is the significance of the statement 'having travelled much in the realm of gold'?

Directions: Answer the given question based on the following passage:

Literature—poetry, drama, fiction—can be enjoyed in two ways: haphazardly as a lay man enjoys it, and methodically as a trained man does. In the one case the impression of its worth is vague, even confused; in the other it is fully accounted for. It is this later method of enjoying that is called criticism. A critic is an ideal reader. Having ‘travelled much in the realm of gold’, he brings to bear a trained judgement on whatever he reads. To him no work of art is good or bad, enjoyable or unenjoyable, meaningful or meaningless, unless he has subjected it to a thorough examination. Criticism is, therefore, born of questioning; it never takes a writer or his work on trust. Where a work is held to be divinely inspired or revealed, as in the case of scriptures, there can be no criticism. For orthodox opinion will not permit a free discussion of it. It is the word of God. Hence it is that for long ages after the establishment of Christianity there was hardly any critical literature on the Bible. It was only when the Renaissance encouraged interrogation and free inquiry that it began to be examined critically. Today nothing is sacrosanct to criticism. It subjects everything to the closest scrutiny. Its approach is that of science—a disinterested application to its subject to understand and interpret it fully. For criticism therefore, as for science, to flourish, intellectual freedom is necessary. It requires an atmosphere in which questioning and inquiry are freely allowed.
It is, however, conditioned by many factors, in particular by the trend of the age and the attitude of the critic. Both these tend to limit the critic’s freedom as indeed they do that of the writer himself. One is ever a slave to one’s times and mental make-up. It is these limitations that make the critical approach of one age or author different from that of another and impart to it is distinctive character. Generally, each age in literary history will be found to have its own critical standards, and each critic his own individual approach. One will look for morality in literature, another for aesthetic pleasure, a third for both. Or, one will advocate conformity to the rules of the Greek and Latin classics, another a reasonable deviation from them, a third a complete freedom of action. And so on. There are, thus, no fixed principles of Criticism to be applied indiscriminately to the works of all ages and writers. What this oft-used phrase actually signifies is the contribution each age has made to critical thought and the course it has followed in so doing. Often the critical cannons of one age have been discarded in another and often too, a subsequent age has revived them. So the principles of criticism are nothing more than the various interpretations of literature or literary activity, advanced from time to time. They are sometimes similar, sometimes dissimilar, and sometimes even contradictory.