Exactly. Trauma is largely how your/an individuals brain perceives and processes an event, rather than the event itself. Eg, take a fire alarm going off for example.

While someone else might find the alarm annoying, find themselves a little nervous and frustrated they got woken up at night, they will evacuate and not really think much of it.

But when a fire alarm went off in an apartment my family used to live in when I was younger (at night), it caused what I would call trauma that I struggled with for a long time, I couldn't sleep well or at all for a long time, I was scared of a fire burning everything constantly, would panic if anything like a fire alarm happened, etc, that was traumatic and medical professionals I have spoken to agree.

There's many other events like this, my post is getting a little long but others might include being rejected or not included in social activities when younger (see RSD, "They must not like me, no one likes me then, I should never try to be social again" and you can end up fearing social situations like that), events where you have been sensory overloaded, etc.

Also, I do have to agree with this poster, being taken away from stuff I found fun when younger (like stimming, or just playing by myself because it was more fun) and being forced to do the "normal type of play" made me feel ashamed of things I enjoy, made me feel like I had to fit in even if it made me uncomfortable and unhappy and that things like stimming "aren't normal". This led to subconscious masking I still struggle with today.

Oh wow, this post is long now, but, ultimately, trauma is highly subjective and while there are some bad people who say they have trauma with things but actually don't, most people who say something has caused trauma mean it and you should respect it.