That is a great question, Anti-Christ, and not an easy one to answer.
To me, in simplistic physiological terms, it is right-brain awareness rather than left-brain awareness. The left brain never shuts up, unless you learn how to to quiet it. It just keeps jabbering and chattering... what the Buddhists call "monkey mind". When you quiet the left (logical) side of your mind, the right side is allowed to notice... and it perceives things very differently than you are used to perceiving them.
I hope that makes sense to you. The best way to describe that difference is by showing you Jill Bolte-Taylor's "My Stroke of Insight".
http://www.ted.com/talks/jill_bolte_taylor_s_powerful_stroke_of_insight.html
Jill Bolte Taylor got a research opportunity few brain scientists would wish for: She had a massive stroke, and watched as her brain functions -- motion, speech, self-awareness -- shut down one by one. An astonishing story.