Fun brutal fact: in addition to the existence of imposter syndrome, being “twice exceptional” (also known as 2e) is also a thing. That means being intellectually gifted AND ALSO having a disability that affects your ability to succeed at study or work. Such as ADHD, autism, dyslexia, dyscalculia, etc etc etc. A lot of people believe that it’s not possible to be both, but it very much is.
Society tends to have very high expectations for how well gifted people will perform. Society tends to have low expectations for how well disabled people will perform. Society tends to attribute invisible disabilities, including mental illness, to a failure of willpower or effort or a bad attitude.
So if you read this post and went “no, but seriously, this is not just low self esteem on my part, people keep thinking I’m smart and then I keep crashing and burning and disappointing them and they can’t understand why I didn’t live up to their expectations, it happens again and again and when I tell someone how I feel and ask for help, they just tell me to stop being so hard on myself and that I’ll succeed if I have more self-confidence,” it is not just you.
(Also, one of the previous posts in this thread buried the lede a little. Imposter syndrome is ridiculously common in people from underrepresented groups in academia and other high pressure/high status fields, particularly women and people of colour. Maya Angelou did not only feel out of place because she was a woman.)