The reason he brought his sisters headstone to the house was because he was re-creating his sisters death in his mind over and over, that's what he was thinking about all that time in the sanitarium when Loomis referenced how "inhumanly patient" he was, that's why he chooses to wear a mask as he did that night, that's why the opening scene freeze frames as the camera pans out after he kills his sister, this is the event that he will be trying to re-create time and time again throughout his life.
When he got to the Myers house, he latched onto the person that he seen, it could've happened to anyone, which makes it more frightening.
Michael represents fate and death itself, Laurie wasn't killed yet because she wasn't meant to be, and death was still out there and would be back for.
That's the idea of Michael appearing behind her at the exact moment that she starts singing "I wish I had you all alone, just the two of us," and the "Don't Fear the Reaper" song playing on the radio, and the scene where Laurie is in class talking about fate as Michael watches her from outside.
None of this depth is present in Zombie's film, and I highly doubt that he understood any of it.
I wholeheartedly agree Stormy, you got it 100% right.


