Pattern recognition is at the very heart of how we learn to play chess. It is the reason that strong players instinctively 'know' what the moves to look at in a position are. It is no use being able to just calculate if you do not know where to begin!

 It is well known that this was one of Fischer's most impressive areas. He was able to play through thousands of games in his youth and he picked up many important patterns and ideas and was able to remember them all (or most of them anyway).