The Question:

* Is that common? 

In Humans, no. It’s rather rare for Humans to seek a career in the magic arts.

In Dwarves and Gnomes, more common that with Humans, but still rather rare.

Most mages are Elves or Faeries, just because of Elves living hundreds of years.

Most of the god-powered mages are very ancient Faeries, often over ten thousand years old.

Learning advanced magic requires centuries of locking yourself away with books and solitary practice. Humans, Dwarves, and Gnomes can never become powerful because they don’t like long enough, so most mages are Fae or Elves. And they are prone to lock themselves in a hermit solitude for 500+ years of intense studying, which results in most of the most powerful mages being extremely eccentric, very antisocial, and often outright raving lunatics. 

Centuries of no interactions cause them to lose touch with reality and forget basic social skills, resulting in the most powerful mages of all, are also often completely off the wall, stark barking bonkers insane.

These extremely all powerful mages are mega arrogant and often quote their near god-like powers as being an excuse why they can get away with not giving two shits about anyone around them.

* Easy?

No.

Magic is VERY difficult and tedious to learn. Thus why so few take up magic arts, even though anyone could do it if they tried.

The problem is that magic is largely will-power/faith/power of positive thinking based. You need 100% self confidence in your ability to cast a spell. If you doubt or hesitate even a little, the spell won’t work, either having a poor result or not working at all. 

So: 

  *   ... someone with a low self-esteem is going to have zero results.

  *   ... someone with a high self-esteem in private but low self-esteem or social anxiety in public, is going to excellent results in the privacy of his own home, but flub, bumbling or zero results at all in public situation.

  *   ... someone who mentally crashes under peer pressure, may get amazing results around strangers, but flub up every spell when his domineering, overbearing stepmother is watching.

  *   ... someone who self absorbed, believes he can do anything, has narcissism/arrogance/sociopaths issues and doesn’t give 2 shits what other people think about him, is going to be shooting absolutely perfect planet destroying fireballs out his ass if he so does so.

Most low level, common mages are shy, timid, bumbling nerdy geeks who can’t cast spells in front of a girl they like, while the mega OP god powered mages tend to also be mega arrogant, self absorbed narcissistic dicks. It’s not always that way, of course, but the averages skew heavy that way. High-powered timid mages exist, and arrogant dicks who can’t spark a fizzle out of their pinkie exist. There are no “low powered mages always ___” or “high powered mages always ___”. But certain personality types are going to have better luck casting magic, so certain personalities dominate certain types of magic.

And...

Because magic fluctuates based on the mental/emotional state (will-power/faith/power of positive thinking) of the mage, his magic abilities can fluctuate. This means sickness, injury, hunger, fears, phobias, sexual arousal, depression, superstitions, religious beliefs, and more, can instantly strip an OP god powered mage of his ability to use magic.

For example:

  *   A mage with the flu is going to be befuddled by stuffy nose and headaches and cannot think clearly or focus well, so even if he was god-powers OP last week, he’s near powerless while he’s laid out with the flu. The same is true if he has a broken leg or gets a stab wound. Any sickness or injury that distracts his mind from heavy focusing on the spell is going to cause him to be as powerless as a non-mage until he’s healed.

  *   A normally confidant OP god power mage, who has a phobia of spiders, may suddenly lose his ability to cast spells if he sees a spider run across the floor. His phobia of the spider floods his brain, alters his mental state, and he can no longer focus on the spell.

This is why when Quaraun is having a panic attack or meltdown, he suddenly can't cast spells anymore.

The mage needs to focus his full attention on the spell in order to cast it. If he’s distracted, the spell will fumble, misfire, or not work at all.

This has a tendency to cause mages to go one of two ways with sexual relationships as well: they either become celibate, often eunuchs, to avoid sexual tension/arousal from distracting them, or they become hyper sex crazed, chasing down prostitutes in brothels constantly, again to avoid sexual arousal being an issue when magic is needed.

This also results in mages being hermits, living solitary lives, having no families/spouses/children/friends/pets, so that these things don’t become a distraction and/or to ensure villains can’t hold their loved one’s hostage to impede their ability to use magic.

Most of the OP mega powered mages are also highly superstitious. A common superstition in many mage circles is that they get their magic from their hair. This causes mages to never shave or cut their hair. For example:

  *   The MC of the novel series this magic system is used in is an Elf with 12 foot long hair. He (Quaraun) is the world’s most powerful mage. In a scene when he is captured by enemies who shave his hair off, he cannot cast magic for nearly 30 years, because that’s how long it takes his hair to reach 12 feet long once again.

  *   The most powerful Faerie mage (BoomFuzzy) has massive dreadlocks that reach to his knees. 

  *   The most powerful Demon mage, (The Gremlin aka GhoulSpawn) is a Cotswold Sheep-man, with the lower body and cloven hooves of a Cotswold sheep, and long ropes of golden fleece cover his waist and legs that grow like Rapunzel hair from his hips and thighs.

  *   The most powerful Dwarven mage (Bullgaar) has a massive beard, hundreds of braids, and requires servants to walk behind him carrying his beard because he can not walk on his own otherwise. His beard is so long. 

All 4 of them wear rings and charms and specifically coloured cluotie ribbons braided into their hair/beard/fur because they believe in the power of specific gems, metals, and shapes causing spell enhancements.

Religious mages may believe their magic to be a “gift from their god” so believe they must live strict rules of that god’s religion in order to practice magic. They may believe they can only cast spells successfully if they light candles or burn incenses or place sacrifices on an altar for example. 

The long hair, charms, and religious rituals do not actually CAUSE the magic powers, but rather the mage’s belief in those things, causes the power, so losing a charm, cutting their hair, or forgetting to light the altar candles that night, will cause the mage to lose his powers, simply because his belief in those things is so strong.

Many mages have wands, staffs, or crystal spheres that they carry with them. These items in and of themselves are not magical. However, mages use them as a focus. The mage focuses his mind and will onto the wand, and the spell seemingly is cast by him aiming the wand. Thus, unmagical people often believe wands are powerful, when, in fact, the wand itself has no power. The mage just uses the wand to direct or aim his focus on his target.

All that said, they do not fully rely belief alone on. 

Real world Voodoo (New Orleans and Haitian), real world HooDoo Rootwork, and real world Enochian Angel Sigil Magic, are used throughout the series. (I am a real world Voodoo priestess and Hoodoo Rootworker, so this is an area I know inside out). Any type of real world magic (Wicca, Witchcraft, Shamanism, Paganism, Heathen, etc) is used by mages in the novels. The MC uses primarily Voodoo and Hoodoo because this is what his Borka lover used and taught him. The Demon mage uses primarily real world Chaos Magick, Demonology, Spirit Familiars, and Enochian Angel Magic.

Because of this, sacred geometry, archangel sigils, sacred words/language of angels, gris-gris, goofer dust, veve, loa, candle altars, jackballs, hoodoo potions/salts/oils/sachets, and similar materials all play a central role in the series.

The 3 MCs (Quaraun the Elf, BoomFuzzy the Unicorn, and GhoulSpawn the sheep Demon) cast huge spells with elaborate ceremonial high Magick rituals that come straight out of real world books by Aleister Crowley, Silver RavenWolf, Scott Cunningham, catherine yronwode, Gerald Gardner, Denise Alvarado, Christopher Penczak, Raymond Buckland, Julia Parker, Derek Parker, Laurie Cabot, Amy Zerner, and Monte Farber (I have all the Wicca/Witchcraft/Magick books by those authors and they act as the source material reference guide I use for my magic system, while working on the novels.)