The process of Awakening is the call of one of the Watchtowers across the Abyss to initiate a human Soul into the Mysteries, forming a Lustrum around a ready mortal to teach them about the Supernal World and guide them into a becoming a mage. A mortal undergoing an Awakening is called a Lucid.
Ultimately, each Awakening is unique, depending on the mortal in question and the Watchtower that he has most sympathy with. Two major ways in which the event may manifest have been identified: the Mystery Play (in which the mage's senses blur the real world and the magical symbolism of their awakening) and the Astral Journey (which takes place entirely within a dreamscape of the prospective mage). In both sorts of "awakenings", the Lucid individual goes on a journey that culminates with them arriving at or in their respective Watchtower and inscribing their name upon it, reconnecting themselves with the Truth and the Supernal realms. Not all mages appear in a literal tower and the process of inscribing does not always mean literally writing your name, but the process always involves a re-connection to the Supernal World by mastering its trials and leaving a mark of your identity within it. As with many things about Magic, the process is highly clad in symbolism. Occasionally, the Lustrum glitches and the Supernal realms are altered in a more extreme way, causing a metamorphic Awakening that retroactively changes the world in some way. The vast majority of the time, this is simply a miraculous healing of the body or mind due to the new mage having corrected her Supernal symbol into something that fits her identity, but it had been known to change history in moderate ways or drawing an Artifact or familiar down with them. In the worst cases, an Exarch might take a personal interest in the Lucid and mark her as a prospective Seer of the Throne, a phenomenon called a Tyrannic Awakening.
A mage can, however, deny the gift of magic. Some remain ordinary Sleeper, while others turn into Sleepwalkers. An Awakening, however, can only be experienced once, and when it is denied first, it can never be replicated. Other supernatural beings, such as vampires or changelings, cannot awaken due to the fundamental changes that occurred to their soul.