I must ask, did you get a university degree and if so how? Personally I have found interviews to be trivial compared to exams in school, so while I do get quite nervous for some of my math examinations I have never had this experience in interviews.
In exams I don't get as nervous because I know that if I know the material then I will pass, if I don't then I won't. You can't bullshit your way past the professor/TA grading your exam.
But in interviews I know that people who are far better than me have failed[0], and that people less competent than me could get the job. So it's not my coding ability or my experience that's being measured here, it's something else. And I don't know whether I have that something else or not. Maybe I do, maybe I just don't.
[0] https://twitter.com/mxcl/status/608682016205344768?lang=en
The canned response I got was "We're sorry, but we can't currently recruit you. Please try again in half a year or so, maybe we will have some new opportunities." If you press on, you just get evasive answers.
I suppose if you went to a great school and then to some shitty interviews, you'd like the school more than the interviews, and vice versa. The difference however is that a teacher is only motivated by their altruism to help you, whereas a company has actual financial motivation to find good people during the interview.
I'm in the profession to write and debug computer programs, not debug people who like to keep me in the dark. This is frustrating.