The Hobbits of the Shire, or anywhere else, for that matter, are an expressly unadventurous sort. In fact, if any of them happen to show the slightest inclination towards doing anything other than eating, drinking, and making merry, they are looked down upon, sneered at, and even ostracized in extreme cases.
In The Hobbit, Bilbo Baggins (played by the astonishingly brilliant Martin Freeman), has a cushy life at Bag End, spending most of his days in a relaxed stupor. All of a sudden, he is dragged into the complex politics of Middle-Earth and has to now learn how to fend off attacks from monster spiders, trolls, and one particularly grumpy dragon.
He Was Actually 50 Years Old
Even though he doesn't look it, Bilbo Baggins is half a century old. It might be strange to consider people at this age going on dangerous thrillseeking missions, but Hobbits don't really age like humans (or Elves or dwarves, for that matter.) It is important to remember that there are a variety of species in Middle-earth, all of whom grow and mature at different rates.
Elves, for instance, are immortal, while dwarves live for about 250 years. In fact, due to his association with the One Ring, Bilbo becomes the oldest Hobbit to ever exist, reaching the ancient age of 131 before disappearing into the West forever.
Bilbo's Hobbit Politeness Gets Him In The Mess
Bilbo might have "grown up" to become a sassy adventurer, but for the most part, he aligns himself with the Shire expectations of politeness. He is never disrespectful, regardless of how he feels about someone, so when Gandalf requests his help in some sort of scam (he thinks!) he gently refuses.
However, the Wizard is far too smart to leave emptyhanded, so he decides to send over the dwarves to Bag End, knowing that Bilbo would have no choice but to cater to his uninvited guests according to his own principles. And the rest is history.
He Was Chosen For His Unique B.O.
Sounds gross, but this was a masterful move on Gandalf's part. Fully aware that Bilbo's small size and general enthusiasm about the world beyond the Shire, Gandalf concludes that the Hobbit would be a massive advantage in the Quest of Erebor.
An added benefit was the fact that the dragon of the Lonely Mountain, Smaug, had never experienced a Hobbit before, and thus would be unable to identify him by smell. Gandalf is of course proven right at the end when Bilbo manages to sneak the Arkenstone out of the caverns without Smaug fricasseeing him.
Bilbo Tries To Pickpocket The Trolls
When the Company passes through the Lone-lands, Balin tells Bilbo to go check out a fire burning a short distance away. Bilbo discovers a trio of Trolls, William, Bert, and Tom, and his brazenness takes center-stage. Bilbo decides that now is the right time to show his indifferent traveling companions that he would make a spectacular burglar.
Bilbo's attempt fails, but he quickly escapes his meager prison; unfortunately, this meant that the dwarves are subsequently captured by the Trolls. Fortunately, Gandalf arrives in the nick of time to play a few mind-games with the monsters, making them completely forget that the sun is about to rise.
Bilbo Chooses Sting
Deep within the Stone-troll caverns, the gang discovers a stash of ancient weaponry. Chief among them are Glamdring (the sword of Turgon, a bygone King of Gondolin) and Orcrist (suspected to belong to Ecthelion of the Fountain.)
In the movies, Bilbo is presented with a dagger-esque blade, which Gandalf thinks would make a fine addition to his arsenal. However, it is the Hobbit who actually picks out the weapon and names it Sting, indicating that he develops a special relationship with it from then on.
He Finds The One Ring By Accident
Unlike the novel, the film version of the One Ring is obtained when Gollum actively misplaces it (in full view of the audience). In fact, this was only done to enhance the cinematic impact; in the original story, Bilbo accidentally finds the cursed thing while scrambling around in the dark tunnels leading to Gollum's lair.
It is quite fitting, since the One Ring is believed to possess Sauron's consciousness, and actively attempts to make its way back to the surface via Bilbo's thieving fingers.
Thorin Doesn't Hate Him That Much
Thorin Oakenshield had no love spared for the clan of Hobbits, at first showing suspicions regarding Gandalf's insistence on including Bilbo in the Company. This doesn't stop the dwarf leader from mocking Bilbo's cushy life, but the extent to which it occurs in the book is considerably less.
In fact, once everything is said and done, Thorin openly admits that "if more of us valued food and cheer and song above hoarded gold, it would be a merrier world."
He Tries To Ditch The Dwarves
While the dwarves empty out his pantry, Bilbo finds himself under extreme levels of stress (his sensible Baggins genes colliding with his audacious Took side).
Bilbo hates the idea of the upcoming adventure so much that he considers going to "hide behind the beer barrels in the cellar" while the dwarves are busy, desperately praying that he isn't caught. Before he can act out his fantasy, however, Thorin sternly asks him where he is slinking off too, forcing poor Bilbo to take his seat once again by the fireplace.
He Helps The Dwarves Escape The Elves
The elves of Mirkwood, also known as the wood-elves, are characters introduced in the later storyline when they imprison the dwarves for creating a disturbance and bothering them. Bilbo's One Ring-based disappearing trick helps him avoid the abduction, and he tracks his friends all the way to the court of Thranduil (Legolas' father).
Rather than break out using force, which would have been impossible anyway, Bilbo stashes the dwarves in a series of wine barrels and tosses them into River Running. This move helps the Company reach Lake-town, their final base of operations.
All Those Rumors In The Shire
Bilbo's narrative may or may not have been as exciting as the one that will develop around six decades after the hobbit returns to Bag End, but, as he would himself state, he has had the adventure of a lifetime.
Though Bilbo spends his time in practical luxury, he has to deal with his annoying neighbors, many of whom begin to consider him an eccentric coot because of all the stories he tells them. The most terrible rumors are actually spread by his malicious cousins, the Sackville-Bagginses, who lose their claim to Bag End when Bilbo turns out to be alive after all.