Impostor syndrome isn't a syndrome. It's a rule you apply without knowing it.
You've been promoted, praised, recognized. And despite all that, there's this voice telling you that you don't deserve to be there. That people will eventually realize you're not up to it. You're waiting to be "exposed" without really knowing by whom, or why.
People tell you it's a common syndrome, that 70% of people experience it, that it's normal. But knowing it's common doesn't change the fact that it's holding you back.
Where the sense of illegitimacy comes from
The feeling of being a fraud rarely comes from an actual lack of competence. It comes from a rule you learned very early, often without noticing: "you have to suffer to earn it," "if it's easy, it's worthless," "you have to be the best to have the right." These rules loop in your head and manufacture doubt, even when the facts prove the opposite.
The exercise below isn't going to reassure you. It's going to help you find the sentence you keep repeating, understand where it comes from, and see what it gives you and what it keeps you from doing.
A rule you've named is a rule you can rewrite
What you just did is make visible a story you were carrying in silence. Most people who experience impostor syndrome don't lack proof of their competence. They have an internal story that invalidates every proof as it comes in.
The Vector path also explores the inherited rules that feed this story, and the autopilots you repeat out of habit to protect yourself from a danger that might not exist anymore. To go further: identifying the inherited rules that decide for you.