It’s call the Dunning Kruger effect. Essentially it says that those who are not competent in a skill will overestimate their ability because they literally don’t know what they don’t know. While people who are competent know how much they don’t know because of their proficiency.

It’s for this reason that it’s important to know that if you sometimes struggle with imposter syndrome you’re not an imposter. If you were, you wouldn’t care or know enough to experience it.