Do not assume that your colleagues can always read your face and interpret your actions. A clear communication of your feelings and thoughts are very important at workplace.
Please read and enjoy the following links for further information about The Illusion of Transparency;
This short video simply shows what The Illusion of Transparency means through a basic and easy to relate example
Fast Company’s popular article about Signal Amplification Bias which is a complementary term that explains one’s awareness about the perception of their message by the receiver
HBR article on impressions and perceptions
An academic research about reading others’ emotional states, published in The Journal of Personality and Social Psychology
A research report about the effects of Illusion of Transparency in negotiations