Big fears are a complex connection of smaller components. Fears generally have a timeline – a when. They have a reason – a why. They have a pattern – a what. They have an outlet, a venue for expression – a how.
Imagine being involved in a terrifying incident where you were physically harmed or threatened. Then imagine reliving that awful memory over and over again, each time as fresh and horrific as when it happened. This is the essence of PTSD.