My Sifu has said a funny statement to us several times, and I thought I should share it. The saying goes something like: "I don't need to keep secrets from you. The secrets protect themselves." Of course, I didn't have a recorder handy, so I have to recreate the quote from memory. Anyhow, it's a pretty fitting [and funny] quote. It is true that my Sifu has never kept any martial arts secrets from us. And even if he did, we wouldn't have a deep enough understanding to realize it (ironic, isn't it?).
Most people training martial arts nowadays train it as a fun pasttime or form of exercise rather than as a serious pursuit. There's nothing wrong with that. People should do what makes them happy. But the lack of serious pursuit does have the consequence of producing few people with deep understanding or real proficiency. That leaves a lot of martial artists out there with limited understanding of their arts and less than real-life effectiveness. It's the limitations in understanding that keep the secrets safe. Not like the secrets are all that complicated; in fact, all of them that I've learned so far fall under the K.I.S.S. (Keep It Simple, Stupid) principle. My Sifu has told me the same things time and again, with only more refinements as my understanding improves.
Everything has been out in the open from the beginning. It's just up to me to train and reflect enough to grasp the lessons so that I can physically manifest the theoretical concepts. Of course, during the process of training and learning, I feel like I've missed an obvious point every time. I slowly realize that what I've just learned has been presented to me several times before. So, I plod along with my training gradually realizing that the "secrets" are pretty simple. Considering the skill differential between me and my teacher, I can safely say that some secrets will remain safely in the open for the forseeable future.