I need to add my two cents here. Even though I am not BPD as far as I know (and no Ts have ever suggested it), invalidation is real and it happens to a lot of people. Asking someone to do something and then redoing it as if your way is plain wrong is bona fide invalidation imo. Another thing I have never liked is being reminded to do something when I am right in the middle of actually doing it! (I can blame my procrastination habit on that I suppose).

The worst for me is getting upset over something I feel passionate about (BIG stuff like violent abuse for example) and other people implying I am overreacting because the world is just like that, as if visible upset is not permissible and my feelings are incomprehensible / stupid. MAJOR meltdown trigger for me!!!