Take your average speculative fiction book and look at the blurb: chances are, you'll see a lot of hyperbole going on in there. "The strongest". "The most powerful". "The youngest". "The brightest". Occasionally it will be phrased as a question — "Could Character A, a lowly etc, be the most hyperbolic etc in history?" If it's YA fantasy, take your average probability and double it.
I can see the appeal. When stuck in mediocrity like so many of us are (myself included), it can be fun to read about people who are extraordinary, who go above and beyond. Many of them are Cinderella stories of talent — orphans who turn out to be the Most Powerful Young Wizard of the Age, that sort of thing — while others are about brilliant, disgruntled characters who know their worth, but have to prove it to others (usually older, less talented, and supremely jealous). People have lapped this up for years.
I'm going to be unpopular now, because I actually hate it.
I love books about ordinary people who end up doing extraordinary things, in spite of themselves and everything around them. The Lord of the Rings wasn't amazing because the characters turned out to be The Most Powerful Hobbits and Men of All Time. It's about perseverance, and loss, and being forced to carry out a task you never really wanted and honestly don't believe you're up to doing. It's about one foot in front of the other. The character struggles throughout the series are phenomenal. Samwise Gamgee is my favourite for a reason; he got into this just checking the gardens, and came back a hero, not because he secretly had a Well of Power within him, but because he was loyal and stubborn.
I'm a little curious why so many books feel the need to make their protagonists The Best. For one thing, it seems a little lazy — if we're told ahead of time that the character is (or could be) The Most Whatever, it seems like a shortcut to the end. For another, it makes the character's personal growth a little hollow, at least to me. Oh dear, Character X has to "deal" with the fact that he's not just a lowly orphan, but in fact has more power than anyone has ever seen. Um. Wah? Very little is compelling about these characters to me, and authors have to work even harder to make me like their characters. I absolutely adore "Ender's Game" and "Ender's Shadow", but even then I kept rolling my eyes at Poor Ender/Bean, the Misunderstood Genius.
Writing aside, I think it's actually a dangerous idea to propagate in YA fiction. Kids have a hard enough time as is — so why do we keep teaching them that the only real heroes are the ones who turn out to be the smartest, the strongest, the most powerful? In the end, it doesn't matter how much other characters may work (Vegeta and Hermione come to mind) — the protagonist's intrinsic power (whether he or she realizes and accepts it at first or not) is what trumps all. Ash Ketchum kept winning Pokemon battles for no reason other than the fact that he's Ash Ketchum — even though Gary trained more, worked harder.
For kids who know that they're the Hufflepuffs, not the Gryffindors, it can be frustrating. Why even bother?
It certainly was to me when I was younger. Faced with book after book of brilliant, genius, superbly talented children whose biggest problem was getting adults to listen to them, or low-spirited waifs who discovered their Power Within, I quickly grew discouraged and disgusted and turned to books with protagonists who weren't the best, but struggled through to win anyway.
I'm perfectly aware I'm in the minority here, so fire away!
This is a real-life example of exactly the sort of heroes I like to read about, but don't often see.