The definition of a "trauma" is an event that has left a lasting effect upon self/psyche. As you explore your goals with your therapist you will target behaviors/reactions/beliefs/emotions you are forced into that you do not desire and others you are prevented from manifesting that you would prefer. Unless the cause is purely organic (a comparative rarity) there will generally be contributing experiential factors. These are considered to be either large or small t traumas. A clinician well-versed in EMDR is trained to help you indentify the contributing events and help you to process them. You should begin to notice changes within a few reprocessing sessions. For precise examples of reprocessing effects, you might want to read some case stories in EMDR (Shapiro & Forrest, BasicBooks). It will give you an idea of what successful EMDR therapy looks like.