*Disclaimer: I really enjoyed the Lord of the Rings Trilogy. Now, I am not a scholar on the books, so if what I'm about to write about isn't true to the characters (as deemed by a LTR superfan), then please forgive my ignorance. What follows is simply a casual observation and not in depth character analysis.
Bilbo was an adventure junkie. He was quirky in the first place, and branching out to new worlds and new things was a way he accepted himself and came to understand that his unique personality served a purpose outside the shire. He never stopped relishing past adventures or wishing for new ones. He never forgot that the world holds possibility and opportunity. The threat of loneliness and isolation that are a part of many adventurers did not compare to the delight of living a life like no one before him had done. Adventure met him and he never looked back. He embraced it even though it further separated him from the world and the people he grew up with.
Through circumstances out of his control, Frodo was called to adventure he did not want. He did not want to bear such a burden on his shoulders, yet understood that the consequences were grave if he did not. He sacrificially shouldered a weight that no one could fully appreciate, and was tormented by the task assigned to him in exchange for an epic experience. His life was meaningful and necessary to more than just himself, and its impact so great that it affected the well-being of generations to come all over the world. Upon return, he withdrew from his peers and found it difficult to interact in the merriment that was his culture. The gravity and depth of his journey left scars that never lifted. At a young age he left normal life permanently and joined a community of people that were not his own, but who could somewhat understand and appreciate the life and choices he had been forced to make. After Frodo saved the world, he was never again able to fit in the life he that was once his.
Adventure came to Sam too. His loyalty to his friend had him volunteer as support on his epic journey, helping him bear the weight of his burden. Certainly Frodo would never had made it without Sam. Though Sam walked as many steps, through as many lands, and faced similar hardships along the way, he was not consumed. He wasn't sure if choosing to join the adventure would keep him from all that he dared to dream back at the shire, but he knew and accepted that it might. Yet what he did know on any given day was that he was where he was supposed to be. When Sam returned to the shire, the adventure he was on gave him the appreciation and courage to live fully where he was at, taking nothing for granted. He lived fully in the shire, then fully in the Grey Havens when the next phase of his life came to pass. He had the rare gift of being able to live well in every place, and the adventure he was on in his early life fueled this.
Adventure, in some form, calls each of us. Some seek it; some avoid it; some fear it; some despise it; some believe it justifies their meaning. For some it is their kryptonite, and others their cocaine. How about you - is it your identity or your biggest fear, or are you somewhere in between? Are you happy with who adventure is making you? Do you ever stop to think that all roads unavoidably shape us, no matter what roads they are.
My life has had a lot of opportunity for adventure, of many kinds. I have been accused of being a junkie for it, but that's not how it feels on this side of my skin. It's hard for me to know what my life looks like from a "normal" vantage point (whatever that is). My opportunities are greater. My ties are less obvious. I've moved more than most people (conservatively, 23 times in less than 14 years). I've seen more than most people. I don't know who all of this is making me into, and I don't know that the adventurer always is the only one who decides. As mentioned before, adventure has risks and side effects... not returning the same is one of them. As I pull out onto another road, I'll keep you posted :)