Definition
If you do something despite yourself, it means you do it involuntarily, even though you do not want to or know you should not.
不由自主地
He laughed despite himself, knowing he shouldn't.
他情不自禁地笑了，尽管他知道自己不该笑。
She agreed despite herself, though she hadn't intended to.
她不由自主地同意了，尽管她本来没有这个打算。
He was determined to stay calm, but he became excited despite himself.
他原本决定保持冷静，但还是情不自禁地激动起来。