Last month, Rachel Rueben shared a post which stated, in part, that children can understand sarcasm by age six. It also said that people with frontotemporal dementialack the ability to understand it. I wasn’t terribly surprised about the comment about children. My granddaughter, who turned 9 in September, is possibly the most sarcastic child on Earth. I can’t confirm this scientifically, because I don’t know every child on Earth. However, I do know my granddaughter, and she’s extremely sarcastic. (You see my line of reasoning, it’s sound—ish) Considering that she comes from a long line of sarcastic people: her parents, their parents and their parents, it’s really not surprising. It will be interesting to see how her little sister fares in this sarcastic environment. I lay bets that the younger one will be even more scathing and sarcastic than her older sister. But give her time, okay? She’s only…