Bernard Werber. Empire of angels (№ 9220)

Anecdote: "one type comes to a doctor. The high hat. He sits down and takes off his hat. The doctor notices a frog sitting on his bald skull. He approaches and sees the frog as if rooted to the skin.
- How long have you got? - he wonders.
Then the frog says:
- You know doctor, first it was just a small wart on his leg"
This anecdote illustrates the concept. Sometimes people make mistakes in the analysis of events, because the only point of view that seems obvious.