Trigger warning are absolute BS. If half as many of these kids that think they have it actually have PTSD then we are doing something VERY wrong to our kids. PTSD is the new ADHD.
The problem is that that they have not been taught that you can at your core hate what someone is saying, and want to disagree violently, and still have a debate or discussion continue without shutting down.
They have been taught from early on that just because they have a thought, it must be their truth- so everyone is running around following their own religion.
Life doesn't have warning labels, shit happens, a parent's job is to raise a child who can handle life's trials (mostly) on their own. Parents are mistaking their kids for friends and doing none of the hard work of getting a child in control of their thoughts and emotions.
My 3 year old when angry/upset/injured generally resets by stopping, taking a deep breath, and gathering himself mentally. He does this on his own without prompting most of the time.
My 18 month old does the same with prompting. It wasn't easy or fun to take a wailing baby and coach them through calming themselves down, but now they can do it- and when life hits my 3 year old in the face, often literally, he practices tools to calm himself down and regroup that these 'adults' can't even manage.