I quote from an interesting (and I think very well written) review of TLJ (emphasis mine):
Lucas was a devotee of Joseph Campbell, a scholar of comparative religion and mythology at Sarah Lawrence College, who had spent his career exploring what he called “the monomyth.” This is the great story which, despite all sorts of different accents and emphases from culture to culture, remains fundamentally the same and which conveys some pretty basic truths about nature, the psyche, human development, and God. It customarily unfolds as a “hero’s quest.” A young man (typically) is summoned out of the comfort of his domestic life and compelled to go on a dangerous adventure, either to secure a prize or protect the innocent, or subdue the forces of nature. In the process, he comes to realize and conquer his weakness, to face down enemies, and finally to commune with the deep spiritual powers that are at play in the cosmos. Usually, as a preparation for his mission, he is trained by a spiritual master who will put him quite vigorously through his paces. Campbell was particularly intrigued by the manner in which this story is concretely acted out in the initiation rituals among primal peoples. Lucas’ mentor was Campbell, and Campbell’s teacher was the great Swiss psychologist, C.G. Jung, who had spent his career exploring the archetypes of the collective unconscious that play themselves out in our dreams and our myths.
Now one would have to be blind not to see these motifs in the original Star Wars films. Luke Skywalker is compelled to leave his mundane home life (remember Uncle Owen and Aunt Beru?), and under the tutelage of Obi-Wan and Yoda, he overcomes his fears, discovers his inner strength, faces down the darkness, and learns to act in communion with the Force. Attentive Star Wars fans will notice, by the way, that Yoda pronounces a number of the well-known sayings of C.G. Jung. I referenced the philosophia perennis (the perennial philosophy) above. This is a standard set of philosophical and psychological insights shared by most of the great spiritual traditions of the world, and it provided the inspiration for Jung, Campbell, Lucas and hence the Star Wars films.
Coming from this point of view, argue why the Rey character is not a "Mary Sue". I found this to be a pretty compelling argument for her character to be labeled as such, and I was initially very taken by her character. My daughters love her, and we don't mix politics and Star Wars at my house (although Disney doesn't have the same scruples, I'm afraid) so this is my only outlet. My daughters are too young to be jaded. I love their idealism and their innocence, and I'll protect it as long as I can.
I am not labeling you as an ignoramous, so please don't take what I am going to say as an insult, but I find many Star Wars fans are guilty of the same lack of understanding of the driving force behind that mythos as they are regarding JRR Tolkein's. Many fans of the SW franchise don't really have a full understanding of the influences on Lucas (or Tolken, fwiw) and his story.