These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: I Know What You Did Last Summer
Adaptation Displacement: The movie is far more well-known than the novel at this point; people who seek out the book may be shocked that it's a character drama about the guilt the characters feel over the hit-and-run (a little boy in the novel) and having to cope years later while dealing with the title-based note.
Disowned Adaptation: Lois Duncan has openly stated she detests the movie, as she was appalled they turned her suspense novel in which only the hit-and-run victim dies into a slasher film, especially in light of her own daughter being murdered in 1989.
Ensemble Darkhorse: Helen, so very, very much. There's no shortage to the fans that wish she had been the final girl with Julie dying.
Karla has quite the fanbase as well.
Fanon Discontinuity: I'll Always Know What You Did Last Summer Many fans ignore it for having no connection to the previous two movies, it's been also criticized for it's writing, acting and characters, and there's The Reveal that Ben Willis is now a ghost or zombie.
Moral Event Horizon: The teens in the first movie, as they decide to throw the body into the ocean to avoid going to jail for DUI and vehicular manslaughter. The Jerk Jockreally crosses the line because he dives in after the body, to make sure it stays sunk. While there, he's the only one who sees the Eye Awaken of the victim, meaning he KNOWS that the victim is still alive! He just swims away, then pressures the others to keep the secret when they start to relent.
Special Effects Failure: When Tyrell gets hooked in the neck, the blood coming from his neck is obviously CG. It disappears into thin air, and none of it stains his T-shirt or skin.
What an Idiot: Barry knows someone wants to kill him. Said person even tried to run him over. So what does he do? Why, he ends up going up to a dark, secluded balcony all by himself.
Helen is no better. After a relentless pursuit, she runs through an alley and comes upon a parade full of people - only to stop and check if the killer has caught up to her yet. Naturally, she would've gotten away if she had just kept running. Of course, she could not have seen the Off Screen Teleportation coming...
And in the second film, Julie is trapped in a tanning bed that's been turned up to the highest setting. When her friends discover her, they immediately set about trying to bash the bed open. None of them thinks of unplugging it first so Julie doesn't burn to death.