This is presumably because the chess master understands the position. I see three pawns, a king, a rook, and a knight. The chess master sees a castled king.

This is presumably because the chess master understands the position. I see three pawns, a king, a rook, and a knight. The chess master sees a castled king. I see 30 pieces all over the board. The master sees the Sicilian Dragon Harrington-Glek variation. I have no idea what happened next. I see eight candidate moves. The master sees three but knows that only one will make this particular opponent uncomfortable. With this level of understanding, it is way easier for the master to remember the game.