Ultimatly, 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 mage-to-be goes on a journey that culminates with them arriving at or in their respective Wachtower 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 is literally writing down your name, but the process always involves a reconnection 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.
A mage can, however, deny the gift of magic. Some remain ordinary Sleepers, 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 occured to their soul.