guilt

He suffered from deep guilt after realizing he had forgotten his mother's birthday.

(Chinese) 在意识到自己忘了母亲的生日后，他感到深深的愧疚。

The thief was so overcome by guilt that he decided to return the stolen money.

(Chinese) 那个小偷被罪恶感淹没了，决定归还偷来的钱。