Poker Face (noun): an impassive expression that hides one's true feelings. Having a poker face is both a gift and a curse. While you can hide your thoughts and feelings from everyone else, a lot of people will think you're arrogant and unemotional. In a lot of circumstances, it is helpful because you want to hide how you're feeling. But on the odd occasion where you are opening up to others, they find it hard to believe because your facial expressions do not correspond to how you claim you're feeling.

7. Sometimes people take your sarcasm seriously.

Or assume you're kidding when you're not. It's just very difficult.

8. People think you're always confident and in control.

You might be anxious as hell in reality or extremely under-confident, but they never seem to know.