Although subjects and questions aren't the same, on the topic of (avoided) questions; anyone unable to answer a question shows you've reached the peak of their knowledge, and anyone unable to answer multiple questions (in a row or close succession) shows you've exhausted their information supply, they don't know the truth, move on, and anyone who refuses to answer a question, shows they don't love the truth, and you should move on. Keep asking questions until you find Someone who answers you and leaves you in such awe that you find you're unable to reply/form other answers.

Followed a similar pattern to that for years. It's kept me from falling for a lot of old hack.