Bias and noise — systematic deviation and random scatter — are different components of error. - Daniel Kahneman

Highly intelligent women tend to marry men who are less intelligent than they are.

When the question is difficult and a skilled solution is not available, intuition still has a shot: an answer may come to mind quickly — but it is not an answer to the original question. The question that the executive faced (should I invest in Ford stock?) was difficult, but the answer to an easier and related question (do I like Ford cars?) came readily to his mind and determined his choice. This is the essence of intuitive heuristics: when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

You know you have made a theoretical advance when you can no longer reconstruct why you failed for so long to see the obvious.