Before the transformative process called The Awakening by many mages, a character is usually part of the oblivious masses who don't believe in magick or anyone having the power to re-write reality itself. They might have been religious, spiritual, or what the Technocracy refers to as "an Enlightened Citizen", but they were only a potential candidate, one of thousands.
And then SOMETHING HAPPENED.
They experience Epiphany, their Avatar explodes into their consciousness, they see and feel and taste and touch and hear the Patterns of the Tapestry all around them. Wild Talent might burst from them, chaotically warping reality beyond their control for a short terrifying and awe-filled while. Chances are that, on a metaphysical (or hyperscience) level, they shine like a beacon- or a firestorm- and might possibly attract the attention of any Awakened in the vicinity.
It is possible that other mage had already chosen them as an apprentice and intentionally created a situation that would encourage their Awakening. If they are really lucky, their new mentor has beneficent intentions. Some sects, like the Order of Hermes and the Progenitors, prefer to find candidates and train them rigorously in a manner that causes their Awakening to be a gradual, disciplined, proceeding.
The Technocracy calls it Empowerment rather than Awakening, the moment when Enlightenment begins and one's Genius begins to burn brightly. It strikes like a lightning bolt or typhoon and changes the character forever. A mage becomes bonded to its Avatar in what will be the most intimate (and probably dangerous) relationship they will ever know. The more powerful the Avatar, the more benefit the mage can reap from it- but there is no such thing as a free ride. A powerful Avatar can be monstrous and show no mercy to its mage as it relentlessly plunges him or her onto a Path towards Ascension.
Awakening is often painful, often terrifying. It can drive the infant mage into the eternal madness of the Marauders. A character's entire belief system might be shattered- and the paradigm that emerges out of the ashes might have the creative power and glory of a phoenix... or be something as cold and authoritarian as Big Brother. Either way, the new mage realizes that reality is their new sandbox- and that includes not just random patterns of energy, but the distinct patterns of energy called people.
A number of mages kill themselves (accidentally or on purpose) within a week or so of Awakening, especially if a mentor doesn't show up to save the day. The collateral damage caused by their Awakening will attract the attention of the mage factions- who are always watching for the signs- and they will send someone out to retrieve the character- or kill them. Sometimes retrieval agents of warring factions collide right into each other and the frightened, confused baby mage gets to witness the blood and gore of what happens next.
But Awakening are not always nightmarish. For some mages, that first moment of seeing the Tapestry, of being touched by their Avatar is something instinctively sacred and exalting. It can be both extremes at once. Just before Awakening, a character might undergo a period of spiked extrasensory awareness and suddenly start to see or know things they never could before.
Mages can Awaken at any age, most commonly at late adolescence through young adulthood. Those who Awaken at a younger or older age often do so during or in the wake of a severely traumatic event. Widderslaintes, Nephandi who inherited the twisted Avatar that belonged to another Fallen in a previous incarnation are often tragic, but not pure of corruption and darkness before their Awakening. They are already marked in personality and beliefs, even if they try to repress these traits, with the latent monstrosity within.