He apologized as soon as he realized what he had done. In actual fact he wrote a nice little note to me.

他一意识到他所做的一切就道歉了。确切地说，他给我写了一张友善的小便条。

《柯林斯英汉双解大词典》

He threw it into the sea before he realized what he had done.

他还没意识到自己做了什么，就把它扔进了海里。

youdao

For many months he was in constant pain, but somehow it healed, and after many years he fully realized what he had done.

好几个月他都处于持续的痛苦中，但是不管怎样还是痊愈了，在很多年之后，他才完全意识到自己做了什么。

youdao

When Yegge realized what he had done, he decided to take it down, though he did not ask others to take it down, notes Rip Rowan in his resharing of the post.

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When I asked him what he had done when he realized that the popularity of the song was exploding, he mentioned three things.

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