What doesn't make sense considering they're ignoring the sequels

Maybe the movie will try to explain this, beyond just simply PTSD.

Remember, Michael murdered his sister at age 6. Then he escaped 15 years later and immediately returned to Haddonfield to kill again. Laurie and Dr. Loomis were the only people who understood how dangerous he was and were able to stop him. Now that Loomis is gone, perhaps Laurie considers herself the protector of Haddonfield. No matter how long its been, or how old he is, if Michael Myers is still alive, then he's a threat to escape and return to Haddonfield for more carnage.

Also maybe we will learn of other escapes by Michael, where he was recaptured before reaching his home town.

How many of the original movies are considered part of this continuity? 1 & 2 only?

I think the explanation will be something like she saw him unmasked so she saw the true evil in his eyes and she knows that he needs to be stopped, also she kinda got away so maybe he will come back to finish the job.

Totally agree...

I mean, she did come across the bodies of her best friends, and they were murdered by a man who had been stalking her ALL day. She probably feels responsible for their deaths for not alerting the cops sooner. Laurie witnessed Michael stalking her four times (outside the school, passing by in his car, waited for her behind a bush, and was even right outside her window). In today's day and age, any man who would've stalked a woman like this would have had cops on his ass, and placed in handcufs. And to top it off, he just wouldn't die. She stabbed him in the neck with a knitting needle, he got back up again. She poked at his left eye with a coat hanger and stabbed him with his own knife, he got back up again. He got his hands wrapped around her throat and got right up in her face with the heavy breathing shit, and she removed his mask to see his face, right before she witnessed/heard him take 6 bullets to the chest, fall off a two story balcony, and he got up again. She was bound to have PTSD from day one, she has enough nightmare fuel to do so.

To top it off, its possible she became obsessed with Michael, and its possible she talked to Loomis about Michael and what makes him tick, and Loomis probably tried to help her but to no avail. And ever since that night, Laurie has become quite handy with a gun. Its to ensure herself that she can take care of herself against not only normal every day folk who want to mess with her, but in case another Michael Myers, or THE Michael Myers were to ever come back and harm anyone else. Laurie needed help, but no one gave it to her, and she spent 40 years letting that night eat at her sanity.

You try having a masked serial killer murder all your friends then chase you around trying to do the exact same thing and see if you casually forget about 40 years later.

You complete and utter moron.

Doesn't make sense to me either.The sister thing gave credence to Michael's obsession with her.Without that connection she's just another random unimportant victim in a psychos path.Why the hell would he give a crap about some random stranger who got away one night 40 years ago.

Going by the trailers, I agree. Its hard to buy that she would be so devoted to reliving a traumatic incident that happened to her 40 years ago. But she did get married and have a kid. Maybe they'll explain that this vendetta is something she only gets reinvested in every Halloween season. I'd be ok with that reasoning.

Plus, she's old and looks retired. Geriatrics need hobbies.