Someone can be traumatized and not even know it. What do I mean? Sometimes people don’t connect the event that happened to them with symptoms they are experiencing. For example: A lady was robbed (Event) while walking to her car and the guy had a knife. She now has trouble sleeping due to nightmares, is snappy with people, and every time a door slams she jumps. The lady is depressed, has isolated herself, and only goes to work and back home. When a friend points out her behaviors she attributes them to having a stressful job. 
Trauma is when an event(s) occur that disables a person’s ability to cope affecting them physically, mentally, emotionally, and socially. The lady mentioned above has been affected in all four areas. Not all four areas must be affected in order for someone to experience being traumatized. Some examples could be someone that got in a car accident and doesn’t want to drive anymore, death of a love one, a divorce, bitten by an animal, domestic violence, sexual abuse, emotional abuse, natural disaster, illness, witnessing a traumatic event such as a car accident, shooting, etc.
Trauma affects the brain and it does not function at its best. There is good news! Her mind works fine. She is able to drive to work and back home and carry out her duties at work. However, there is a very small part of her mind that has not been working in her best interest and that is what I would work on adjusting. I would first educate her on what is going on in the mind. Research shows that if a client understands what is going on in their mind they accelerate in therapy. 
For adults the average time I see clients is 1 – 6 sessions. How can this be? I use techniques that work specifically with the part of the mind that believes the event is still happening. That is what makes an event traumatic. The biggest challenge we will ever have in life is right between our ears, the Mind. There is nothing wrong with having a mind tune-up every now and then. Everyone could use it!