To grasp just how much operates beneath your awareness, consider this finding from Tor Norretranders' book The User Illusion:
Your subconscious brain processes approximately 11 million pieces of information every second. Your conscious mind handles a maximum of about 50. That means in any given second, you are consciously aware of roughly 0.00045% of the information your brain is working with.
Put another way: if your subconscious processing were represented by a full calendar year, your conscious awareness would cover about 14 seconds of it.
This isn't a minor gap—it's an almost incomprehensible one. When it comes to understanding why you do what you do, your subconscious holds virtually all of the answers.