I have always believed that regret is a necessary course in life. Because you have regrets, you will cherish them more. Regarding the two protagonists of the story, if I have to describe them, I think they are a combination of longing and helplessness.
They have experienced a lot, lost a lot, but also gained a lot. The past drifts away with the wind, time passes like smoke and clouds, and people who come and go gradually drift away, parting in waves.
But all this is to become a better version of yourself.
There is no need to regret, they will eventually meet on the broad road in the future.
Purpose: Growth and regret are compulsory courses in life