See, that's the best part. It's what makes people "fall into" Middle Earth. That there was whole parts of the backstory that don't get explained. That there are

See, that's the best part. It's what makes people "fall into" Middle Earth. That there was whole parts of the backstory that don't get explained. That there are periods of history you get a glimpse into to believe there is a huge depth to it. That the way we see the continent now is not how it always was. Who were the barrow wights? Why were they cursed? As a kid first reading it, I feared the barrow wights as much if not more than the Nazgul. The whole aside was to show that the hobbits had truly "left the Shire" and that perils lay along the road in any direction they might turn. But, again, there were allies or, at least, guides all along that road as well. Bombadil and Old Man Willow are a foreshadowing of the Ents to come.