i feel silly posting this, but i used to be top 3 in an old fps when i was 15 or so, we were having what was the most influential clan match of all time when it first happened to me, i started playing flawlessly (hah) and i noticed that i no longer had to actually focus on the match at all, it was exactly as day[9] described it, things slowed down and sped up at the same time, and i felt as if i was watching myself play and my hands weren't my own (i distinctly remember looking at the keyboard and mouse in amazement, but it must have been my imagination unless i was playing using peripheral vision, very strange). i saw things before they happened and enemy mindgames became a joke. i think it worked because i had seen every possible situation in that game over and over and knew the best answer to all of them (or was able to think up new answers on the spot), but it was a very technical game and the key was executing them
i'm 24 now and i've been chasing that feeling ever since, i get glimpses of it playing melee.