I was reading a Brokback Trivia site yesterday and came accross this......
Director Ang Lee gave Heath Ledger and Jake Gyllenhaal copies of the book, "Farm Boys: Lives of Gay Men from the Rural Midwest", by Will Fellows, a book that had been mentioned by both Annie Proulx and Diana Ossana as an excellent reference source, to help them understand their characters. Noting what he learned from his reading, Gyllenhaal said, "I dont't think that these two characters even know what gay is"