While the world they knew before was no more, the unfamiliar world and reality they now found themselves in were starting to become familiar.
At the start of the apocalypse, only a few people were capable of dealing with zombies. Now, while the numbers haven't increased to an extreme state, the amount of people who could handle zombies to weaker monsters has increased compared to how it was days ago.
It was just as the popular saying goes: the greatest trait of humanity was their ability to adapt.
Aside from this, it was also their ability to learn.
The apocalypse had only arrived a few days ago, but humanity had already been able to gather a significant portion of knowledge about their new reality when put together. Of course, it was nothing compared to the bigger picture, but it only went to show just how much humanity now understood about the apocalypse.
