I agree with LiuHeQuan above (sorry, I can't bring myself to use the cantonese).
The construction of ancient forms is something very few people understand. The poetic sequence and abstract moves conceal a vast amount of martial knowledge. But without the 'Key' it is invisible to you. People don't realise much of traditional wushu is abstract, the stance reflects the principle clearly but doesn't always reflect the technique clearly. The principle is more important because in reality the technique will never be the same as in training, but the principle, the formula, will be.
But I will say that actually there are no secrets as such, everything is there in front of you, but in order to understand it it takes a lot of time. No one really holds stuff back, but if your skills are not good enough, they simply won't teach you.
A Master and disciple is a special relationship. The master wants a good disciple as much as a disciple wants a good master. Without the other neither could exist. A master will freely teach you everything, If he thinks you have the potential to learn. If he's not teaching you stuff it is because you are not good enough, or because he has nothing to teach, he's not keeping secrets.
As people have been saying Chinese Gong Fu is an entire lifestyle, it certainly not just some fighting skills. Fighting skills can be learned quite fast, but to understand TCMA does really take many years.
Training for health is far more practical than training for combat, because you are many times more likely to die of poor health than die in a street fight. I'm sure this was always true, even in the times of bandits and warlords.