Eventually, Earth is like it was before Humans, and slowly it becomes like it was when it was young, except now it is old. Then it is gone. And then everything is gone. Things are now back to the way they were when Bob first came out of the Nothing. And we are back where we started.
Time is a loop.
It has no beginning and no end. Each step leads to the logical next step. You see this loop mirrored all over the world. Just go to a science class and you see pictures of the water cycle, the air cycle, etc. Even the life of humans mirror this cycle.