Trivia: When they were shooting the scenes for the start of the film (all the ones seen from Michael's POV) they couldn't get the 6-year old child actor until the last day so the movie's producer, Debra Hill, volunteered to be Michael for any scenes where his hands come into view. This is why the nails on young Michael's hands look so well manicured and varnished.
Trivia: John Carpenter and Nick Castle were school chums, and upon shooting Halloween, when Castle visited Carpenter, he was originally only going to hang around the set. Carpenter saw that Castle had the right proportions for Michael Myers, and said "Well since you're going to be here, why don't you do something? Here, put on the mask and you can be the killer."
Trivia: In addition to being an old film-school pal of John Carpenter's, Michael Myers actor Nick Castle is ironically enough also quite well-known for several more family-friendly projects that serve as a stark contrast to "Halloween." He's also a filmmaker who co-wrote several films including Steven Spielberg's "Hook" and the uplifting drama "August Rush", in addition to directing the 80's classic "The Last Starfighter."
Trivia: This is just an observation but almost everyone Michael Myers kills (or tries to kill) sings to themselves when they are alone - maybe that just really annoyed him or something.