mind-boggling

伊坂幸太郎氏の小説 "Remote Control" を読んでいます。パート4，The Imcidentから引用します。

He had never been to the model shop. Koume Inohara had bought the helicopter and even put it together for him, so the scene on the tape had never happened. Still, there he was-in a still extracted from the footage now filling the screen--or someone who looked exactly like him. It was mind-boggling.

"mind-boggling" の意味を調べます。

・Oxford English Dictionary: very difficult to imagine or to understand; extremely surprising: a problem of mind-boggling complexity
・Collins Dictionary: If you say that something is mind-boggling, you mean that it is so large, complicated, or extreme that it is very hard to imagine.: The amount of paperwork involved is mind-boggling.
・Cambridge English Dictionary: extremely surprising and difficult to understand or imagine: She was paid the mind-boggling sum of ten million dollars for that film.
・Vocabulary.com: intellectually or emotionally overwhelming: “a mind-boggling display”

正月の初セリのマグロの価格は私にとって "mind-boggling" です。