I am surprised that you didn't have at least one class on World Religions at the seminary.
It seems to me that as a future pastor you should have been encouraged not only to study theology but also to study humanity, the better to minister to your flock. Ancient myths can offer many insights into how the human mind works, and how people down through the ages have viewed their relationship to the divine powers that shape their lives. And many of these beliefs still hang on. The popular conception of God expressing his displeasure with thunder and lightning bolts -- is that really based on the Bible (where God seems to have a heck of a lot of ways of expressing his wrath), or are we seeing echoes of the old pagan gods like Thor and Zeus?
And fantasy, the best fantasy anyway, is not merely about make-believe. It's about inner realities: our dreams and impulses, and the things that the heart knows but the rational mind is incapable of expressing directly. It is the same with myths, fairy tales, legends, folk lore. Although there may have been quite a lot of nonsense mixed in over the centuries, there are still some important insights into human nature to be found if one looks at these things with more than a casual glance.
So I hope your time here is not a waste but a chance to expand your mental horizons, to the benefit (ultimately) of those you serve not only to council them on a spiritual level, but also as a counselor when it comes to their everyday troubles and dilemmas.
And on another note, I believe "known thine enemy" is a maxim based on the idea that it you can figure out how your enemies think you can predict how they will act, and therefore be more effective in defending yourself and/or turning their own strategies against them.