Below is a link to a buried treasure with the “Q&A with Gygax thread” on EN World.
Therein Gary Gygax and a fan named Diaglo have a humorous debate over the origins and effects of Magic Missile.
It was hilarious back in November, 2005, just as it is today. Kudos to EN World in keeping this, and other gems, archived.
May it bring you some Christmas cheer today.
(Also, check out this video at Dorks of Yore where Tim Kask explained how he convinced Gygax to let Magic Missile always automatically hit).