When your ears are assaulted by revelations from someone you don’t know, cut them off, leave, do what you need to do to end the blather.
No one who suffered certain traumas, regardless of what they entail, shares them with strangers or people they are not close to.
They are telling you because they need to continually resuscitate that false memory. They need to hear their voice confirming what didn’t happen.
On the opposite side, people you’ve known all your life who begin to tell you something completely off the wall, something you know couldn’t have happened, find out if they were recently at a psycho-therapist.
When they say yes, probably with surprise, quickly pick apart their fantasy.
If you are successful, you’ve saved them a lifetime of grief.