1. Luna Lovegood arrives at introductions night on a thestral.
  2. Parvati and Padma Patil's occupations are both "Twin."
  3. There's at least one veela contestant, and everyone else is super jealous of her.
    There's a lot of, "Harry, I don't want to name names, but I'm going to name one anyway..."
  4. Cho Chang gets the first impression rose
    She gets eliminated towards the end, but becomes the next Bachelorette.
  5. There's a quidditch group date.
  6. There's a Diagon Alley group date.
  7. There's a Dumbledore's Army group date where Harry just watches everyone cast patronuses for a few hours.
  8. Romilda Vane is the one that gets drunk at every cocktail party, and is constantly taking Harry aside to "talk for just a minute."
    After she's eliminated, she goes on Bachelor in Paradise.
  9. Lavender Brown confesses to Harry that she is embarrassed about her "warlock toes."
    She also goes on Bachelor in Paradise.
  10. Love potions are strictly prohibited, and a few contestants are sent home for trying to make them.
  11. The dream suite dates take place in the Room of Requirement.
  12. The date cards usually arrive by owl, but occasionally Harry apparates into the room to hand deliver them.
    Contestants also use apparition to interrupt others' conversations, although this is frowned upon.
  13. Chaos ensues when the remaining three contestants discover that Harry drank Felix Felicis immediately before the overnights.
  14. At least one contestant calls Harry "CHARMing" and then laughs at their own joke.
  15. Harry proposes to Ginny Weasley.
    Their hometown date at the Burrow definitely sways him.
  16. They always have to act surprised when a one-on-one date includes a private Weird Sisters concert, even though they're pretty much the only band in the wizard world
    Suggested by @jenna
  17. Harry, after talking to Lavender: "My head hurts - and, trust me, it's not because Voldemort's nearby."
    Suggested by @jenna