Clause + とは

[To think that; how surprising that]

Connection: Clause (plain form) + とは

Usage: Used to express surprise, disbelief, or shock at something unexpected. The speaker did not anticipate the situation and finds it remarkable. Often followed by expressions of surprise or left as an exclamation. Can convey positive surprise, negative shock, or simple astonishment.

Examples:

まさか彼が合格するとは思わなかった。(I never thought he would pass.)

こんなところで旧友に会うとは驚いた。(How surprising to run into an old friend in a place like this.)

あの真面目な人が遅刻するとは信じられない。(I can't believe that such a serious person would be late.)