THERE'S ALWAYS ONE PERSON

without fail/murphys law/etc.
  1. Who corrects a typo of a teacher even when it's obvious what the word is
  2. Who talks on the quiet car of a train
  3. Who asks the question that was just answered by a supervisor/professor
  4. Who comes in & orders 'for here' 5 minutes before a restaurant closes
  5. Who will enter a room halfway through a movie or show then ask 20 questions trying to figure out the plot