They turned what was supposed to be a fun night into a nightmare for everybody. 

It’s no fun to be in a situation where you feel like you can do nothing right. You always commit some slight transgression that enrages someone who can’t regulate their emotions, and it ruins all the fun. Have you ever been to an amusement park with someone who pitches a fit because they want to ride their favorite ride first, despite everyone else wanting to ride another ride, forcing everyone to «compromise» by riding the ride the fit-pitcher desires to ride? Or maybe you’re making a holiday dish for your family’s Christmas or Thanksgiving, and one aunt just can’t shut up about how she likes her green beans boiled, not the way you prepare them. 

It’s hard to move on and forget that someone is so upset about something so minor, even if you think their complaint is foolish. We all have an innate human desire to please those around us, and when complaints about banal realities turn into the biggest problem in the world for someone in your social circle, it can be really difficult not to internalize those complaints.