He does not actually use the term spiritual awakening, but it is clear to see how his quest resulting in him opening his heart and becoming more tolerant of others.  I think that the awakening process is not an easy journey, and some people can find it quite difficult.

Some people talk about it in very physical terms, like having strange sleep patterns and vivid dreams and experiencing unusual sensations.  The sensations are described as tingly, itchy or prickly.  They are often on the head, scalp or around the heart area.  They can also be felt in the feet.  People might experience sudden rushes of energy that feel uncomfortable.  Dizziness, falls and feeling spacey are common and can be experienced along with sudden cellular memories surfacing.  People reconnect with past lives or parallel universe experiences.  This can be quite disturbing and disruptive. Some people feel troubled and like they are going crazy and losing their sanity.

Others talk about emotional changes, sudden outbursts of energy, crying fits, overwhelming joy or depression.  Many people find themselves dredging through old stuff and feeling the pain of old events or experiencing a return of old symptoms. This can lead to fear and confusion and a sense of wanting to sort everything out. This can involve changes of diet, friendships, de-cluttering and dealing with addictions.

Changes of weight, eating habits, cravings or desires can also occur.  There may also be accompanied allergies or intollerances of specific foods.  Rashes and skin changes or discharges of any kind are not uncommon. 
Heightened sensations are very commonly reported.  These can include seeing things in more detail, or brighter or being acutely aware of sounds or sensations.  The tastebuds become more discerning as does the sense of smell.  Many mystics report smelling flowers or rose petals.

There can be a kind of intensity in the approach to a project or work, an obsessive drive to carry out a mission.  This can be accompanied by a feeling that the project is being divinely inspired and guided. Increased prayer or meditation or communing can feel absolutely crucial. This perhaps separates the above symptoms from other conditions like menopause!
Along with the rushes of energy and the intensive drive, people describe power surges. Emotional life changing events occur, like death of close ones, divorce, illness, betrayal or any other difficult events. They force people to deal with unresolved issues.  
Strange coincidences occur and people or things appear just at the right time.  New skills and talents emerge and sharpen alongside a sense of purpose.

For some people this process can be quite sudden, in this case Simon's awakening took more than 5 years as he reconnected with his former selves.  It has fundamentally changed him as a person and it has not been an easy journey.  The all consuming awakening impacted on every level of his life. However, the good news is that there was light at the end of the tunnel and a much more peaceful and joyful state emerged.  This book is a brilliant read for anyone experiencing a similar process.