I feel the experts pain (if this is a stress related thing). I get freaked out under any interviewing. If the interview was hostile I would forget my own name. Parts of my brain just refuse to function under such situations and I'm not exaggerating. I.e. I know what a newton-rhapson iteration is supposed to do but cannot remember it nor derive it from first principles. Although, I suspect I've also relied a bit too much on google when these sort of things pop up professionally (which would make search engines a critical part of my higher reasoning )