Imposter phenomenon (often referred to as imposter syndrome) seems to be a common experience for JavaScript developers, and it's not surprising given the breadth of the language and its penetration.
We tend to think of imposter phenomenon as having a solely individual basis, whereas psychological research points to environmental and social aspects as well. Accordingly, we need more focus on improvements we can make to work environments and the JavaScript community to minimise the prevalence and impact of imposter feelings.