What is Trauma?

What we commonly call trauma is a fragmented recollection of events that were created when so much fear or grief was present that the thinking part of your brain shut down. That's why there are no traumatic events--only traumatic experiences. The shutdown of thinking from the excessive fear or grief is the cause. Not everybody has the same experience at the same event. Some people suffer intrusive memories after and some don't.

Traumatic experiences often occur around experiencing--or even witnessing--these sorts of events:

Natural disasters (floods, hurricanes, tornados, earthquakes)
Accidents (auto accidents, plane crashes, boating mishaps)
-Sexual assaults
Childhood or other abuse
Violent arguments
Life-threatening moments (robbery, warfare, other uniformed services)
Many others

These memory fragments dwell in the hippocampus of the brain (not in the cerebral cortex or long-term memory) as sensory memories (because your thinking shut down, but your senses continued recording) awaiting the thinking part (cognitive memory) to join them so they can consolidate as long-term memories.

These fragments intrude because, for you, they've been going on in the here/now since you had the experiences because they are stuck where memories are formed--not where they are properly stored.