It's not so much that your subconscious is convincing your dream self that you are awake...it has more to do with specific areas of consciousness and logic centers that are normally powered down when you are dreaming. As paige said, the key is practicing awareness, and learning how to turn those areas of the brain back on inside a dream. Some people will naturally have a much easier time of this than others, and a lot of it has to do with luck and life circumstances as well.