" My friend Julie was cooking dinner in her kitchen one night. Her expression was blank as she stood alone working by herself. Her daughter walked in and gasped, “Mom! What’s wrong?” She said “Nothing. I’m fine.” In response, her daughter added, “Then tell your face! You scared me!” Emotional expressions can easily be misinterpreted when we are not aware of what people are seeing. Being deep in thought can look that way. "

― Susan C. Young , The Art of Body Language: 8 Ways to Optimize Non-Verbal Communication for Positive Impact (The Art of First Impressions for Positive Impact, #3)