The best place I’ve found for hunting down fantasy ideas is a library (or your favorite local, independent used bookstore).
If I look up from my computer I can see books with titles like these – A Dictionary of Angels, Arab Folktales, Tokyo Underworld, Mythical Trickster Figures, American Indian Myths and Legends, Greek Homosexuality, The Complete Prophecies of Nostradamus, and the History of Grave Robbing.
I think the word you’re looking for is: eclectic.
And, actually, this represents one shelf. I’ve got books of much greater range stashed all over the house.
The best reason for becoming a writer is because, when all else fails, you’re often a hit at cocktail parties. Because we’re trolling dark and strange places for ideas, writers know the weirdest stuff – and we know it passionately. When I get on the thread of something, I’ll follow it all over the place. Often my original intent gets lost among all the cool side streets.
So, I think if you’re trying to cultivate the heart of a fantasy writer, you need to develop the passions of a researcher.
Or, as I said in class, it helps if you naturally think too hard about stuff. (God, I’m so articulate!)