Told to BUZZ OFF by Sesame Street Inc, Bernard tried various lines of work, but his insanely contentious mindset made any long term employment impossible.
He tried a lot of things, and perfected failing at all of them...
You don't need to be friendly to sweep up elephant dung or to be a cab driver in New York. And surly waiters are certainly a thing... But I assume he kind of went overboard with the attitude...