It is highly unusual that you would have crohn's disease but never had a single flare.
Regarding locaton of disease. In the overwhelming majority of patients crohn's disease only manifests itself where bacteria are present. The ileum, the colon, and in the mouth in the form of aphthous ulcers. It is often said that crohn's disease can manifest itself all along the digestive tract, that is simply not the reality.
The few cases described in literature about esophagus involvement likely have nothing to do with crohn's disease. They are far too rare, and bacterial populations above the ileum are insignificant compared to populations in the lower digestive tract.
For crohn's disease to manifest itself, you need large populations of bacteria. Mouse models have clearly shown you can not mimmick crohn's disease in sterile environments. Only the mouth, ileum and colon have the bacterial populations required to evoke the inflammation seen in crohn's disease.