Many times during an attack,
the knight can go safely to e7. But once there, what to do? Notice
that on e7, the knight takes both g8 and g6 from
the king. If Black's g pawn is still on its original square, then
White has made a solid wall that keeps the King pushed to
the side. If you notice this fact, you should be able to see the mate.
It's just like a back-row mate, only on the side of the board instead
of on the back row.
Club members made several
other suggestions about how White could get another mate. But all those
idea had the same problem: Black did not have to make the moves that would
lead to the mate. Anastasia's Mate leaves Black no choice. Every move
of White is a check, so Black has not time to wriggle out of the mate.