Phonemic awareness

If my understanding is right, phonemic awareness(PA) is that people can hear, indentify and manipulate phonemes in their language use. As cited in Freeman and Freeman, Stemovich indicates that PA is the key factor to diferentiate good readers from poor readers. How did this come? Is phonology the only factor that matters in reading or not? I wondered that.

So, is PA learned through direct instruction or it can be learned subconsciously? I think the two different views--word recognition & sociopsycholinguistic view both partly make sense. I believe it can imporve one's PA skills through word recognition; however, I really do not know how to learn the phoneme without any instruction or without any conscious learning. Based on my L2 learning and teaching experience, I suppose that PA need to be learned in a conscious way first and then it may be subconscious acquired when one's phnology knowledge is good enough.

Wait, is my view under the influence from the traditional concept of learning in Chinese culture? According to that, one should master certain amount of knowledge to become able to use it. ?? My APP is going to drive me crazy, I guess.