We must have been burgled while we were asleep.

我们睡着时一定让贼入室偷了。

《牛津词典》

On another photo of two relatives asleep in chairs after Thanksgiving dinner, my Dad left a voice comment in which he joked about how exciting the dinner must have been.

另外一张照片是我的两个亲戚在感恩节晚餐后坐在椅子上睡着的情形，我爸爸在语音评论里开玩笑称晚餐时他们一定玩疯了。

youdao

I must have been asleep.

我肯定是睡着了。

youdao

He couldn't believe they didn't stop him, but thinks they must have been asleep.

BBC: The Great Escape

Jones, Obama and the rest of their gang must have been asleep when the Saudis, Egyptians, Jordanians and the rest of the Arabs told them that Iran is unrelated to the Palestinian issue and that Iran must be stopped from acquiring nuclear weapons regardless of the status of Israeli-Palestinian relations.

CENTERFORSECURITYPOLICY: Barreling on, regardless