* When Michael Myers murdered his sister Judith on Halloween night, he was dressed up in a clown costume. You might wonder if that means anything. It does, because that makes him a MonsterClown, and clowns have had a long history of existing and behaving outside the rules. That's right, Michael is essentially ComicBook/TheJoker of slashers, engaging in random killings and behaviour from childhood!
* From part 2: several times throughout the movie, Michael's eyes are clearly visible in close up through his mask. [[spoiler:At the film's climax, Laurie shoots Michael's eyes out.]]
* While people usually mock the sequels(especially 4&5) for not having good masks for Michael, it actually makes a lot of sense in-universe. After the ‘78 murders, Michael’s original mask was likely put out of production, given the murders committed while wearing it. So it makes perfect sense that there wouldn’t be a proper mask anymore!

* When [[spoiler:Lynda is killed in the first film, her final thoughts must be that Bob, her boyfriend, is the one attacking her. She never saw Michael Myers, and just assumed that he was Bob in a sheet ghost costume playing a trick on her. She then turned her back to make a call, and Michael murdered her with the phone cord before she saw him. I suppose it doesn't make a tremendous difference either way, but still, the poor girl thought it was her boyfriend strangling her to death]].
* When Michael escapes in the first film, he lets out a bunch of patients who acted like harmless, drugged-out zombies. [[spoiler: But Michael can't be the only murdering psychopath in the place, right?]]
* In the 5th movie, we see Jamie getting rocks thrown through her window, because of what she did, and because she’s Michaels niece. Sucks for her, but think for a second. What did the people do to Michaels parents after he murdered Judith, and Laurie after the 78 murders? Laurie might have lost some of the heat given she didn’t know and killed Michael, but just imagine what Mr. and Mrs. Myers might have gone through.

* In the 1978 film, when Laurie tells Tommy and Lindsay to go to the [=MacKenzies=]' house and have them call the police, why didn't she just go with them? What was keeping her there, anyway?
** She's exhausted, injured, and thinks that Michael's dead and no longer poses a threat to her. She probably figured that the best thing to do was stay put and rest until the police and ambulance got there.
* How does Michael know how to drive a car in the first film, given he's been incarcerated in a mental institution for 15 years, since he was six?
** This was actually brought up in the first film itself, with Loomis making a guess that "someone around here must have given him lessons." But, that proposes a bigger question: why would a member of the staff give Michael driving lessons, even more so, how would they be able to without even Dr. Loomis knowing about it?
** I think Loomis's lessons line was more sarcastic then anything. Michael likely just payed very close attention to the drivers actions when he was in a car.