Old Brom the storyteller—sure, he's good for a forbidden tale, or to answer your questions about dragons, but do you really want him coming along on your heroic quest, grumbling all the time and whacking you with sticks? If you're Eragon, you bet your sweet bippy you do. After all, every good hero needs a guide.
Class is in session. Here's your stick, Eragon, now duck!
Brom is the ultimate teacher, tasked with training Eragon in the old, lost ways of the Dragon Rider. And, no, he's not giving out gold stars and happy faces. These lessons are tough and painful because Eragon's enemies are also tough—and into pain (as in, dispensing it).
Still, there's no ego in Brom's instruction. He's focused solely on making Eragon better than he is. And when he does reach that level? "We're done for the day," Brom says (31.33). "I can teach you nothing more of the sword" (31.35). It takes 31 chapters, but Brom does his job. He teaches Eragon a valuable lesson: strength comes from experience.
Of course, there are also magic lessons, and combat strategy, and…well, the list goes on. But throughout it all, Brom works tirelessly to help Eragon graduate to the level of a bona fide Dragon Rider.
What qualifies Brom to give all of these lessons? We're glad we asked. He himself was once a Dragon Rider. Of course, he only confesses this on his deathbed, keeping his own exploits hidden and focusing instead on preparing Eragon for his own challenges.
As it turns out, Brom's dragon was also named Saphira, but she was killed when she was young. A couple important things to mention here:
(1) Brom killed the guy, Morzan, who was (indirectly) responsible for killing Saphira. We have a feeling that will be important.
(2) The loss of his dragon buddy is what inspires him to go all rebel. We know that's important.
This all puts a whole new spin on Brom's relationship with Eragon. Think about some of Brom's final words to Eragon: "Guard Saphira with your life, for without her it's hardly worth living" (37.20). For one thing, we see him giving advice to the young Rider, even up to his dying breath. At the same time, we see how Brom might have vicariously gotten pleasure from spending time with the new Saphira, and from seeing her in action. In her, and in her Rider, Brom's legacy lives on.
Brom has definitely seen a few episodes of Buffy. And not just because of the whole demon slaying thing. He also knows what it means to be a watcher—to take on the role of mentor to the hero who will save the world.
Even though he's acting as the town storyteller, we're guessing Brom was watching Eragon all along. It's pretty clear that he knows what's up—all the stinkin' time—and that it's no coincidence that he's there when Eragon needs him.
The whole watching-over-Eragon thing really turns Brom into a father figure for the fatherless Eragon. When he's alive, we might think he's a bit overbearing and crotchety (like the best parents tends to be), but not just anyone will take a dagger for Eragon. Once he's passed on, we realize how important he was to Eragon. Check out what Eragon inscribes on Brom's tomb:
HERE LIES BROM
Who was a Dragon Rider
And like a father
May his name live on in glory. (37.37)
These words are all-the-more touching because Eragon never knew his real father. After his uncle Garrow dies, Brom comes along to fill the space left by that father figure. Of course, Brom mainly berates Eragon for being a big dummy, and he pummels him every night with a wooden stick, but Eragon comes to appreciate Brom's instruction and friendship. Their bond becomes so intense that, after Brom's death, Eragon wants the world to know that Brom was a friend, and so much more.
And the feeling is mutual. As Saphira tells Eragon, "Brom also wanted you to know that of all the people in Alagaësia, he believed you were the best suited to inherit the Rider's legacy" (38.44). Sounds like a pretty sturdy relationship to us.