Everything with shooters now is twitch reflexes and speeding around catching people by surprise. More so than back in the CSS days and I sucked at CSS. 6 months ago I would have been consistently massacred in a COD multiplayer match because I was so out of practice. It takes me a few weeks to get back to the level of competitive against normal players and much longer for my muscle memory to start working again to the point where I can even begin to defend myself against the sweatlords flying around the maps.