A trauma is an incident. The significance is in your emotional response, not in what happened. The same incident is no big deal for others, but it is, or was a big deal for you.
Here is an example from my life:
I went on my biweekly grocery shopping trip with the old folks van yesterday.
They asked what’s new, and I shared that I asked the Community Center to give me a chance to do a short lecture on water. The answer to that was a groan. Audible, and coming from a deep reluctance and distaste.
It wasn’t the right time to deal with it then and there, so I stored it away for analysis later.
And this is “later”… let’s do it now.
First off: the groan awakened a whole series of memories, unpleasant memories of earlier similar incidents.
Earlier similar is a technical term.
Let me explain:
When you are upset, you are never upset from or by what is happening right now.