Someone says something. Or doesn't say something. And in seconds you're gone — checked out, shut down, over-explaining, or already planning your exit.
You don't decide to do it. It just happens.
Afterward, in the quiet, replaying it, you know exactly what you wish you'd done differently. You had the words. You just couldn't get to them in time.
That gap between who you are when you're calm and who you become when you're activated? That's not a character flaw. It's a skill gap. And skills can be practiced.