Where for, and what happened? I'm pretty happy in my minimum wage overrun hellhole of a job, it must be said.
Do you want the job? or just the money? if its only the money then big deal, NEXT!! If its the job, well most of the interviews I thought I ****ed up I got offered the job..... Perhaps that says more about me though...
Must have be the way you wear that hat at a jaunty angle. Sorry to hear about the interview. Having been to a few myself last year and conducted 100s in my life the best advice I can give is don't panic and don't worry. Be yourself, if they will not empoloy you for who you are it's not the job for you. If you don't know the answer or don't understand the question, own up. Some interviewers purposely ask difficult or impossible questions to see how you react under pressure.
Don't worry mate I know the feeling I screwed up an Interview with Accenture this time last week as it happens. Just put it down to experience and move on.