"Man, when I was younger I shoved my ignorance in people’s faces. They beat me with sticks. By the time I was forty my blunt instrument had been honed to a fine cutting point for me. If you hide your ignorance, no one will hit you and you’ll never learn." p.135 Fahrenheit 451 by Ray Bradbury.
What does the instrument the author is referring to in the given passage represent in this context?