Getting triggered!

Ever been chilling, out and about, hanging with your boo, friends,etc? And all of a sudden something that someone says/does reminds you of your ex, ex boyfriend, girlfriend, friend and as a result you feel triggered, you feel afraid, scared, confused? How did you feel when you were triggered? What did you do to handle the trigger? Did you revert back to your old ways? Or did you find a better way to handle it?