One day in high school, I casually infuriated one of the other boys. (We were all boys, and therefore the place was so full of adolescent macho boneheads that I didn't even notice I was one of them.) He had made a physically aggressive gesture toward me in the parking lot, and rather than simply ignoring him, as a mature person would have, I had responded with a calculated show of disregard, making it insultingly plain that I didn't take his threats, or him, seriously.