As The Hunger Games: Mockingjay - Part 1 opens in Singapore tomorrow, some might remember a time when young-adult fiction and movies made from the novels were just called "novels" and "movies".
If a genre needed to be given, the film might be dismissively tagged as "teen" fare or, if it was more posh (or European), blessed with the term "coming-of-age film".
But the astounding success of the Twilight series sent tremors through Hollywood and, in its wake, the Young Adult, or YA, template was created.
The studio accountants loved it, but for many others - including film fans - it was yet another sign of Tinseltown's creative bankruptcy.
To understand why YA movies are the genre du jour (in the same way that Star Wars, Jaws and Indiana Jones created genres and started a flood of me-too works), it helps to understand how financially conservative Hollywood has become in recent years.
With fewer and fewer people turning up in movie theatres in America, films these days are greenlit on factors such as built-in marketing (is it based on a best-selling property?) and foreign market appeal (will people in China understand the story?).
Properties like that do not come along every day, so this is why films based on the Marvel Universe are now huge. But they are expensive to make - they tend to feature top-earning actors (Robert Downey Jr as Iron Man, for example).
Mistakes are costly, so expensive branding exercises are the norm - witness the all-out campaign to raise awareness for this year's big hit, Guardians Of The Galaxy, which saw the cast touring key Asian cites, including Singapore, earlier this year.
Enter the young-adult novel. It has a few defining characteristics: a teen protagonist (often female), a romance fraught with difficult choices, with a finale that sees her coming to terms with herself and winning love and respect all around.
Movies made from these books have all the safety factors that make studio heads happy, with the bonus that they do not require expensive star casts. Like the horror genre, they are relatively cheap to make and, also like splatter or spook films that break out into the mainstream, break-out YA films can be extremely lucrative.
But what seems to be everywhere now is the subgenre of YA science-fiction and fantasy. Because there is simply more stuff going on - vampires, werewolves, explosions, chases, missions - it ups the chances that it will draw patrons who do not give a hoot about the book or its characters.
Franchisability, scale and spectacle are what separate a niche YA movie (The Princess Diaries, 2001-2004; The Perks Of Being A Wallflower, 2012) from big-budget projects such as The Hunger Games (from 2012), Divergent (2014), The Maze Runner (2014), The Mortal Instruments (2013) and The Twilight series (2008-2012).
There is a template to everything in Hollywood and the basic big-budget action-adventure template is based on the seminal 1949 book Hero With A Thousand Faces by mythologist Joseph Campbell, who described the common threads in hero fables from around the world.
With few exceptions, cash-cow films today stick to the Campbell formula: A young man is born and grows up ignorant of his own greatness. A message arrives telling him of his heroic destiny, which he denies. A death, either real or symbolic, forces him on a journey that tests his mettle. He dies a symbolic death, but is reborn the hero.
This is the biblical story of Moses (once more remade and released this year as Exodus: Gods And Kings, starring Christian Bale as Moses), Luke Skywalker (the Star Wars series, 1977-present) and Neo (The Matrix series, 1999-2003), and the basis for a thousand other movies.
And so it is with The Hunger Games' Katniss Everdeen (Jennifer Lawrence). She is content to be passive, as is Divergent's Beatrice Prior (Shailene Woodley), until outside events propel them on a journey, one that leads them to love, growth and power.
It is the same with The Maze Runner's Thomas (Dylan O'Brien) and The Twilight Saga's Bella Swan (Kristen Stewart).
The difference between the films with young female leads and the traditional action-sci-fi genre is that the romantic element is more prominent.
What is more, the object of her affections is kept in the background, passively watching and waiting, unable or incapable of expressing his feelings for her. She, meanwhile, comes to prove her naysayers wrong as she wins respect and gains agency over her life.
In other words, the YA story is very much a teen wish-fulfilment device: Young women often feel misunderstood, overlooked and under-appreciated and these films offer an escape into a better world.
For that reason, many have been dismissive of YA films as being narcissistic and mushy.
If you feel this way, remember that the films are mostly directed by action directors with little feeling or patience for the art of portraying young love on screen, especially within a dystopic universe with battles breaking out.
Also, we have spent our lives seeing sci-fi and fantasy heroes as white American males, born to save the universe. How is that sort of hero, and his point of view, any more "normal" or less narcissistic than any other kind?
What do you think of Hollywood's foray into young-adult fiction for its movies? E-mail email@example.com