So, I was seven years old (1992).
My daddy used to tell me stories about his favourite movies, one of which was of course Predator. I remember thinking about this "Predator" movie all the time, 'cause he just LOVED it.
And one day he says to me - "Predator is gonna be tonight on the telly, you can't watch it cos it's gonna be too late but I'm gonna record it for you". So I drew a small comic book about Predator without even knowing the plot, the look of the hunter etc. (that's true, I swear!) and I went to sleep.
Next day I watched it and BANG!, it just f**ked me up. I'm a fan since. Not a fanboy, though.
Oh, I watched "Alien" when I was four, but I didn't understand a thing and didn't become a fan. So it doesn't count