Even if I am in a sea of people, I can still see your back at a glance.
It's like I can find the only you among these 7 billion people.
But after all, all I see is your back. Occasionally you will turn back and wave to me, but I can't chase you, I can only watch you drift away.
Because there is an abyss between us that cannot be crossed. I stood there, staring into the abyss, until I could no longer see you. In the end, I could only turn around and leave, even if I knew that moving forward was passing by your world, even if I knew that missing you would last a lifetime.