Laurie Strode: You failed, Michael. Want to know why? Because I'm not afraid of you. But what about you? Are you afraid of me? Are you afraid to die, Michael?
Jim Morgan: Say something smart.
Donna Chang: Existence precedes essence.
Jim Morgan: God, you're sexy.
Donna Chang: Cameras are so... phallic.
Jim Morgan: Is that good or bad?
Donna Chang: Depends who's watching.
Bill: You know, I think it happened when she was right there. Poor little Judith. Helpless, brushing her hair, young and naked.
Jenna Danzig: Yeah. 'Cause that's gonna happen, right?
Bill: Come on, Jen. One flash and you could light up a thousand computer screens. Launch your whole career.
Rudy Grimes: You want some of this? Huh? You want to try and fucking kill me? Huh? You like sushi, motherfucka?
Sara: Rudy, do you ever think about anything other than food?
Rudy Grimes: Wouldn't you like to know?
Laurie Strode: I knew you'd come for me sooner or later. What took you so long?
Freddie Harris: Fear is good. Fear is what gives us the feeling of being alive.
Sara: Fear makes me want to throw up.
Rudy Grimes: Don't distract me.
Jenna Danzig: Oh, I can't help myself. I am distracting.
Answer: At first impression, Laurie was catatonic not only from the shock of killing an innocent man, but also from a lifetime of being chased down by her murderous brother. She obviously knows from past experiences that nothing she does (including faking her own death) will stop Michael from finding her. It is later revealed she has been faking her mental issues (think when she has been hiding her regular meds in the raggedy Ann doll) and is committed only to stopping Michael, no matter what the cost. She may have also been trying to protect her son and the only way to do that is to allow herself to be institutionalized in order to lure Michael there.