why didn't he kill Laurie as a baby?
This is something I always wish they would address on-screen.
The initial reason, and therefore, arguably the real/primary reason is that she wasn't originally his sister, not written or revealed that way in the original, that's something they came up with for the sequel to keep the story going.
Beyond that, one can argue, of course they wouldn't include that, what kind of movie would show that, or even allude to it? Fair, but that's talking about OUR reasons, not an in-universe reason. Just wanted to debunk that before anyone threw it out there.
I mean, I'm not rooting for ultra-violent torture porn here, just saying, in real life, babies do sadly get murdered. And Michael is portrayed as insane, evil, soulless, cursed, and so on. He'd already murdered one sister, why stop at such an easy target? Especially since if you believe the whole Thorn thing, this is his sole objective is to do so. If he's as bad as we're to believe, and completely conscience-free, I don't see him having a soft enough spot to not kill a baby. Especially given that it just brought him more work. Not only because he ended up in a decades-long pursuit of a fully capable adult who was expecting him, but since she had two children, and at least one grandchild. John could presumably be a parent, though, at the beginning of Resurrection, it's stated that four "students" died in H20, and I know that many take that to be Charlie, Sarah, and the two at the beginning, but he states specifically (I just watched, so I'm absolutely certain), the four students as being killed at Hillcrest. Granted, he's a mental patient and also states that the night of the original murders, so being the first and second movies, he also killed three nurses and a paramedic, but it was way more than that. But my point is they could conceivably use that line to retroactively kill John offscreen, saying maybe Michael offed John and Molly quick after Laurie took the van with the wrong guy. Because if they were to ever return to the original continuity, it's anyone's guess if Josh Hartnett would return. But back to my point, Michael made his own work a lot harder by not killing Laurie as a baby. It seems the curse wants satiated.
The only reason I can really think of, which, again, wish they'd have addressed on-screen. He does it to prolong his own life. Because killing is the only thing that gives him satisfaction, specifically going after family members. So if they were all gone, he would cease to have something to live for, and just enter a permanent state of catatonia, or would finally be successfully executed. Putting other people down is what gives him a reason to get up.
Thoughts?