Sad people will make you sad. Happy people will make you happy. Angry people will make you wary. Stupid people will make you annoyed. Miserable people will make you miserable.
Of course, none of that is true when you understand you, and only you should have control over your emotions.
The day you learn to control your emotions is the day you control your life.
Some people will disagree with that premise and tell you somebody else made them feel the way they do, however, I believe a picture is worth to a thousand words. If anybody has control over you, you gave them the reins.
“You cannot always control what goes on outside. But you can always control what goes on inside.” ~Wayne Dyer.
“The goal isn’t to get rid of negative emotions, the goal is to change how you react to them.” ~Anon