The Fact Corrector is allergic to mis-statements of fact. Poor thing, she cannot help herself. An erroneous utterance of a fact causes her to itch severely behind the ear, and she will need to scratch unless she can correct it first. This causes a great deal of trouble for the Fact Corrector, who takes to wearing earplugs whenever she is in public; otherwise, the itching would drive her insane.
If one place is 1.2 miles from another, then one should say so. "Between one and two miles" is sufficient, but "a few miles"? Incorrect! Misleading. Intolerable. How can one say 'turquoise' when the color is clearly 'teal'? Opinions are one thing, anyone can have one, but a fact is a fact is a fact.
1892, not 1896! 'Twelve eleven', not 'a quarter past the hour'! 0.8 inches of rain, not 'a trace'. People have become quite lazy nowadays. Precision used to have some value.
The Fact Corrector keeps all the right answers in her brain, behind and slightly to the right of her left eyebrow - you can see it working to retrieve them on required occasions. A slight twitch as the fact comes tumbling forward. Then the mouth begins to open. The Fact Corrector wishes she could stop, but she cannot. It is as if the facts themselves compel her.
The recipients of her corrections are as grateful as one might expect, which is to say not very. They thought they had left behind such experiences when they were children back at school. Hostile glances are exchanged. Eyes are rolled. The Fact Collector understands but she is at the mercy of a greater power.
The Fact Corrector lies awake at night, worrying that during the day she had made some trivial error, and so contributed to the rampant ignorance which is driving the world to destruction.