We haven't seen each other for a long time, but we are strangers when we meet, which probably means that we won't recognize each other even if we meet again. From now on, we are strangers living far apart.
It can also be said that I don't know and heaven remains our neighbourhood even if I meet him. The definition is: even if we meet in the future, we will not recognize each other. From now on, we will be completely unrelated strangers.
The origin of "I don't know when I meet you" is Su Shi's A Dream of Jiangchengzi.
Extended data:
"Even if you don't know each other, you are covered with dust and your temples are like frost." These three sentences have taken a sharp turn for the worse, taking progress as a retreat, and imagine the unexpected consequences of not knowing each other even if you meet. These three sentences set out from the reflection on the imaginary dead, setting off the author's misfortune and great changes in the world in the past ten years.
As far as the word is concerned. This article is really Apollo's true feelings. The last sentence is painful, but there is joy in sadness. Su Shi, who was quiet in grief, recalled the dribs and drabs when he met Wang Fu, and they clearly emerged in his mind. If life is just like the first time, the memory of first acquaintance is the best in Su Shi's eyes: "Xiao Xuan window, dressing up."
Although, at this time, there is a "window of Xiao Xuan" between two people. Once the "window of Xiao Xuan" between two people's hearts is pierced, when they "care for each other without words", they have mixed feelings "only a thousand tears". At the moment when Su Shi and Wang Fu have a heart-to-heart, silence is better than sound, and only endless tears can express Wang Fu's feelings.