Move your piece out of the way so another piece can act
A square or line that your piece is blocking. Move that piece, often with a threat of its own, and the second piece delivers the blow. You don't see the pattern.
vs game: knight had to move to allow a queen to deliver mate. Played the wrong knight move, missed the mate.
vs puzzle: bishop clears the rank with check, rook slides in behind. Two moves, game over.