"Youth is wasted on the young."
That is one of the oldest (maybe wisest) adages you will hear, and a cautionary tale in one succinct line. Most Romance novels, science fiction romance, paranormal romance, are about young people.
Romance is, obviously, the dominant feature of life when you are young -- looking for it, wishing for it, wanting it, seeing others attain it, yearning to have your life-path changed by an encounter with a true Soul Mate.
Youth, especially the teen years, is peppered with giant miseries. Or they seem giant at the time -- rather smaller in retrospect. Still, such teen-angst is very real, very potent, and very life-determining.
How an individual responds to an angst or misery, a situation of being tormented, bullied, oppressed, or outright abused, of being trapped, forced, and desperate, seems to determine where that person's life will go -- the "destiny" of that individual.
Is "destiny" something you choose by choosing your response to your teen-challenges?
Or is destiny something you are born to -- as the Ancient Greeks depicted -- a decree of "the gods" which, if defied will result in something even worse?
In other words, whether a Character views their Situation (miseries and all) as a springboard into a (very real, tangible, and actual) Happily Ever After lifetime, may depend on their religion, creed, culture, or cussedly defiant Nature.
Is "Destiny" -- a Happily Ever After life is one possible Destiny -- something you can attain only by fighting, battling, risking life-or-death, desperately striving for? Or is "Destiny" something that just happens, and can't be avoided (as the Greeks believed).
What exactly is Destiny?
If it is something you will reach, and have no choice about, then why strive?
If it is something you might attain, if you work hard enough for it, then it is a choice.
In either case, Youth is the inflection point -- somewhere between maybe 15 years old and possibly 29, critical choices are made.
For example, choose to go to college when you are 15, then hurl yourself wholly into academics and win a scholarship, devote every waking moment to studying (not going on Dates), and make it through a Ph.D. -- but in what discipline?
Another choice, then, would be a choice of career, or career direction, and once made, these early, (youthful) choices are very hard to set aside.
Many people, in later years, regret mightily their choices in their teens.
Is the choice, made in ignorance, by the teenaged self actually the real Destiny of that Soul? Or is the actual Destiny chosen in later life -- say 35-45 years of age (the second marriage is the typical Romance novel motif).
This idea is rooted in the concept of Destiny as something that is the consequence of choices made in innocence, ignorance, and Youth.
Suppose in your Paranormal Romance universe, Destiny is set by Birth, written in the genes, or perhaps the Social Status of the Parents?
Once set, once carved into the developing person before the age of 7 years, can it be changed? Should it? What is the price of choosing a different Destiny than is expected of you?
Why should you strive to fulfill the expectations of "others" (parents, siblings, teachers, Authority, Society)? Don't you have anything more important to do?
The answer to that question -- "why should you" -- is a theme.
We've discussed THEME in almost every post -- it is the origin of the opening scene, the Middle Pivot Point, and the final Climax as well as the last word.
Theme is this novel's statement about the nature of the reality the Characters must navigate to get to their Happily Ever After situation -- and what makes those Characters Happy is not necessarily obvious to the reader without a very clear ILLUSTRATION of the theme by the writer's use of symbolism.
Theme is energy of Culture - and it resides in the non-verbal part of the mind, or perhaps pre-verbal. Theme is what you know about the world that you have no idea you ever learned. But you did. You learned your Reality before you were able to form words. That is why few writers begin shaping a story by stating the theme to themselves.
Theme is often something you discover while working through a final polish draft -- and suddenly realizing you need a major rewrite to communicate that Theme to the readers.
If the readers understand the Theme, the Characters will never seem "one-dimensional" or "cardboard" or "out of character to do that stupid thing."
The Character's motivations will be excruciatingly clear to most all there readers to can grasp the Theme -- the single-pointed center of the Character's "reality." The Origin Story of their reality.
So the Origin Story is very important to followers of the exploits of the Superhero.
Two TV Series Superhero properties based on Comics illustrate this point.
ARROW - based on DC Comics superhero Green Arrow, about a scion of a wealthy family Oliver Queen, thought drowned in a shipwreck who survived on an Island learning Martial Arts.
IRON FIST - about a scion of a wealthy family thought killed in a plane crash who survived by being rescued by Monks from "another dimension" (where he learned to control chi and make his fist glow with Power).
IRON FIST is a Marvel property, done as a Netflix Original,
Marvel's Iron Fist: A Netflix Original
2017 TV-MA 1 Season
Danny Rand resurfaces 15 years after being presumed dead. Now, with the power of the Iron Fist, he seeks to reclaim his past and fulfill his destiny.
Do an in-depth contrast-compare study of the first seasons of these two series.
Both these are typical Superhero Characters -- somehow striving to fulfill a Destiny. Broken from their "past" (like Superman was sent to Earth in a capsule as a baby).
They appeal to the youth in us all with the dream of a better life earned by striving.
In the best of these mythical universes, one gets a better life by making the world a better place (fighting crime, evil, whatever invading forces want to ruin good things).
The dream of striving to fulfill a Destiny is mostly a thing of Youth, and with decades of life behind (think Gandalf) most humans realize they never will "make it."
But some (like Gandalf) get another chance before age robs them of abilities.
So to convince your Readers that the Happily Ever After ending is realistic, craft a thematic answer to the question about the nature of reality in your Characters' Universe -- "What exactly is Destiny, where does it come from, does everyone have it, does anyone need it, or even want it, and is Destiny worth striving for because it is Destiny or because it is the HEA condition we all yearn for?"