To know why the mind is normally unable to perceive something completely, let’s see how it works. Typically the thoughts (including the memory) are connected to each other and there is always a tendency for forming new connections and strengthening the old ones. Thoughts can hardly exist without being connected with an existing thought (we make use of this aspect while accessing the memory).
Any stimuli could potentially evoke a range of thoughts in the mind. Assume that these thoughts arise in a sequence. But then there is also a strong urge to connect the ‘first thought’ with an existing one in the mind. Normally this urge is very strong and beyond the control. So abandons the act of forming new thoughts and moves to connecting the thoughts.
The act of allowing as many responses to occur in response to a stimulus without the unconscious urge to form an association is the essence of ‘presence’.
Here is a representation of how the mind behaves while responding to a stimulus:
As soon as the first thought occurs (the first few..) there is an urge to form an association with thoughts in the memory. The association could be based on an event, appearence, place, person, emotion etc. The next thought again tend to form subsequent associations till either the thought links become weak or an exteranl trigger interrupts it or the mind suddenly becomes concious.
The relationship to creativity is simple. Creativity is about forming new thought associations and patterns is about sticking to old associations. The former is the creative way and the latter is the productive way- at deep down this is what differentiates creativity and productivity. You get to choose one, not both; at least simaltaneously.