If I had known this before, why should I recognize it?

If I had known this, why did I do it in the first place?

1. If I had known that it would be so disturbing to people, why would I not have known each other in the first place. To paraphrase, if I had known that lovesickness would be so entangled in my heart, it would be better not to know each other in the first place.

2. If you understand the past, you should not admonish it, but if you know what is coming, you can pursue it. Interpretation, recognizing that past mistakes are irreversible, but there is still time to make amends in the future.

3. Meng Xue knows what day it will be, leaning on the building and looking to the north. To paraphrase, I don’t know when Zhao Xue will be rehabilitated. Standing upstairs and leaning on the railing, looking towards Kyoto and Chang'an, I sighed in pain.