Pessimism is seen as a plus among lawyers, because seeing troubles as pervasive and permanent is a component of what the law profession deems prudence. A prudent perspective enables a good lawyer to see every conceivable snare and catastrophe that might occur in any transaction. The ability to anticipate the whole range of problems and betrayals that non-lawyers are blind to is highly adaptive for the practicing lawyer who can, by so doing, help his clients defend against these far-fetched eventualities. If you don’t have this prudence to begin with, law school will seek to teach it to you. Unfortunately, though, a trait that makes you good at your profession does not always make you a happy human being.
Is there a way to get your mind out of these negative loops? Yes.