When I was in kindergarten there was a classmate named John who was a very disagreeable sort.
I really did not like him.
Later, probably in first grade, a new student arrived named John.
I immediately did not like him.
After a few weeks it came to my attention that the new John had none of the bad attributes of the previous one and the question arose in my mind whether I had made an error.
I realized that I disliked the new John because of his name.
Even then I was loathe to give so simple a rule as “Jonhs are bad.”.
Eventually I made friends with the new John but wondered how you were supposed to tell the difference between good Johns and bad Johns.
The world had become more complex.