About 7 or 8 years ago, while still in school and when all my aspirations as a photographer centered around skiing and mountaineering, a skier-friend suggested that I meet a buddy of his who was an established photographer within the outdoor industry - and even offered to look into it for me. "Sweet!" I thought, and couldn't wait to hear back... When I followed up with my friend a couple weeks later, he sounded disgusted and said something to the effect of, "You photographers are all a bunch of selfish idiots." Apparently his buddy had balked at his suggestion, stating that he had no intention of associating with 'the competition'.
Years later, I encountered a much different philosophy while working with a successful advertising photographer. Even though he was well aware of my intentions to eventually go out on my own, and knew that we would likely compete for jobs (which we have!), he nevertheless shared generously from his wealth of knowledge in order to help me succeed. He was, and continues to be, a great friend and mentor. And, while his success is obviously a result of his creative talent and wise business skills, I like to attribute at least a part of it to good karma.
Ironically, the latter photographer probably had much more in the way of ‘proprietary trade secrets’, and thus much more to ‘risk losing’ by sharing. He also happens to be much more successful of the two. I think there’s something to be learned here. I think we as photographers often assume the stance of the former, reluctant to share our knowledge and know-how with others.
Now, I definitely recognize that maintaining proprietary information has its place. The magician’s motto of never sharing secrets has a striking parallel with photographers. We are, in a way, hired to do the same thing: magically produce surprises out of our little black boxes in a way that no one else quite can. Incidentally, I believe this explains why so many photographers are upset about the preponderance of cheap professional-quality digital cameras. It's like magicians getting upset because WalMart now sells magic kits. But that's just it. They confuse the box itself with the ‘magic’ at work behind it. There’s no way we can coast along if our craft can be reduced to simply a specific camera, lens, lighting scheme, or Photoshop filter.
In the end, I think it has to do with relationships. I'm frequently asked how I do what I do, and my responses vary widely, usually depending on who's asking :)