Before this dissolves entirely into some kind of narcissistic praise of my reflexes, the downside should also be mentioned. Having sharp reflexes can also involve reacting quickly to situations and conversations, the worst kind of 'conversation' being that in which it is possible to type and press enter before allowing the words to fully filter through the thought process. Or more precisely, pressing enter before summing up how abrupt words on the screen can appear in the absence of tone of voice. This is one of the many reasons why I'm not keen on Twitter.
Update: See this for a horrifying example. (How one stupid tweet ruined Justine Sacco's life.)