It is an unsynchronized future, but what does it mean to change the diary in the schoolbag?

Two people have different trajectories, but both want to continue with each other. These words and phrases come from that song last summer. I slowly become dull in the loss, which is an asynchronous future. However, I changed the diary in my schoolbag and extracted fake dust lyrics. "Last Summer" is a song sung by Wang Damao, composed by every family, and included in the album "Last Summer" released on May 18.