An analogy would be traveling in the brain jungle, where your conscious mind might not be able to recall the specific routes, your foot nevertheless leave marks in the jungle that make later traveling on the same paths easier or possible.
All in all, answers to problems like this become very obvious once we separate our so-called conscious mind and the inner subconscious zombie that in fact does most of the mentally/bodily processing.
For example:
1. Do you know all your vision can "physically" see at any moment is only about a thumbnail's size at an arm's reach, yet your inner zombie construct a vivid 3D environment.
2. What if I lower your house's keyhole by 2"? You would still reach for the old spot then realize something is wrong. But who's remembering the old location? Not your conscious self (otherwise every moment you type a key you have consciously validate). The memory keeper is your inner zombie.
