Tom Bombadil is a being so powerful and strange that even his creator did not know what to make of him.
While fans and scholars have speculated and disputed his nature, they neglect to consider that the man who discovered was himself wise enough to refrain from doing so. Tolkien respected the mysterious nature of Tom Bombadil. He did not fret with Tom but simply left him be in his corner of Middle Earth, a corner which by Tom's mere presence is perhaps the most unusual and miraculous of that map.
Since I am rather well-read in Middle Earth lore, casual Tolkien fans sometimes ask me if I know who or what Tom Bombadil is. But in all my years of enjoying Tolkien's lore I have never found an explanation concerning Tom Bombadil that satisfied me, but one.
It seemed a fact not worth mentioning that the character of Tom Bombadil was inspired by a Dutch doll that belonged to one of Tolkien's children. While this may go so far as to explain some of the very specific and colorful attire Tom is known for wearing, such as his yellow boots, as well as Tom's carefree and almost childish nature, it does not at first glance say much else about the ancient figure; till you learn that Tolkien used to tell his children stories about that doll.
While reading Tom's own songs about skipping through the trees and along river beds, one can almost picture Tolkien bent over his children's beds, the shadow of the doll cast across the bedroom wall as he animated it with his hands and his voice, bringing it to life with his stories.
Tolkien told his children stories long before he ever actually completed writing one that satisfied him; and so, one can know with certainty that Tom came along long before Bilbo or Hùrin, or even Gandalf.
These were only shadows cast big and small, vague impressions in Tolkien's mind left by the lore he loved and the legends he read. Names of characters he later wrote about can be found in obscure Norse fragments we know Tolkien used to study. Images resembling Tolkien's own line some of the Fairie realms he once dwelt in.
But Tom Bombadil was there, real, tangible, childish, put forth with the easy flow of a narrative told for one's own children, living up only to their whimsical standards, and not Tolkien's own. Tom offers us a glimpse into what those stories might have been like, there in the bedrooms of his children when he did not burden himself with self-doubt and a work beyond imagining in the course of an evening.
It is strange that something that at first seems so easy should puzzle readers for so very long. Tolkien did not wish to understand Tom Bombadil. Indeed, while most everything else about Middle Earth is rich with history and thought, Tom Bombadil exists outside of that, he escapes that, in more ways than one.
We must decide that Tom Bombadil must simply be left be.
In the end, the only thing that has ever made any amount of sense to me about Tom Bombadil was what Gandalf says about him. At the Council of Elrond, he tells that Tom "is oldest."
Tom is older than Middle Earth both inside Tolkien's works and outside of it. Indeed, out of all the vivid faces and scenes that linger when I reflect on all I have loved in Middle Earth, I know Tom Bombadil has been around the longest. He was around long before any of Middle Earth's histories were written, for he lived outside of them once. He knew Tolkien before he was weighted by success and immense writings.
I know only that Tom Bombadil is so ancient that the only origin I have ever traced of him in all my Middle Earth wanderings is the curious and puzzling figure of a Dutch doll in yellow boots. And where that came from, none but Tolkien need ever know. Though I greatly doubt that he himself would have been able to remember.