If time could go back, Song Zhou hoped to go back to the night when he was eighteen years old
If she really goes back to that night, Song Zhou will definitely take her to escape from the vanity fair of nothingness.
It's a pity that time always moves forward without stopping, never giving us a chance to retreat. Even "if" is just a coward's regret later.
Purpose: Any suffering is not a reason for us to commit crimes