If you let a yappy little dog upset you then you’ve given that yappy little dog power over you. You’ve given a little dog power over your emotions. Just think about that for a moment. Horrifying and stupid, isn’t it?
Likewise, if you let people upset you, the you give them power over you. You give them power over your emotions. Do you really want to give them power over you?? Really?
If you say it’s their fault for making you angry, you’re wrong. It’s your fault.
Take a deep breath or two, relax, smile and remind yourself who’s in control.