Who says i "don't understand" it? Just because it's an effect doesn't mean it's the explanation. By the definition of gaslighting being pretending you're imagining something that's actually happening, this is exactly what that is. Just because you don't understand gaslighting doesn't mean that everything that you don't understand can be explained away in terms of documented effects. Things happen and you can't explain them...the world and other people's opinions don't conform to some list of effects that you know about.
You know this: https://news.ycombinator.com/item?id=26970960
I agree with you that the term gaslighting is overused but that doesn't mean there aren't legitimate uses of it that you can also utilize.