Public speaking - Public speaking is a personal hell for an introvert. From forced speeches in classrooms to giving a toast at a wedding, having an audience is always terrifying.
Parties full of strangers -
Introverts will find two or three close friends and stick to them like a magnet the entire night.
Networking - Should your job growth really depend on how well you can banter? Introverts quickly realize that networking is just socializing while wearing a suit.
Crowded spaces - When there are so many people on the street that you just want to curl into a ball on the ground.
Group participation - Group participation, whether you are in school or at work, is so difficult for introverts.
Talking on the phone - Talking in person can be stressful enough for some introverts—adding a technological barrier definitely doesn't help. Let's not even talk about FaceTime.
Being told to be more social - When you're an introvert, people will tell you all the time to "be more social," as if that's all it takes.
Last-minute plan changes - Some introverts have to mentally prepare for social interaction. So when a last-minute plan changes things, this can be incredibly frustrating.
Being ignored - An introvert may be more quiet than the rest of the group, but that doesn't mean they have nothing to say.
When people are late -
While not everyone is the punctuality police, some introverts can't stand it when people are late.