Believe it or not I saw GF1 at a drive in with my parents when I was 7. Sonny being shot freaked me out so much we had to leave, my folks were very young as well and did not realize how violent it was, as I recall the horse's head scene was pretty traumatizing too.

I didn't see it again until I was in my 20's and saw GF2 as well, been hooked ever since. Still need to read the books tho. I only recently saw the Saga with the deleted scenes.