I've lived here all my life, and I've been through quakes before. But this one felt different — not because of how big it was, but because of all the bad things that happened before.
It was 8:30. My brother had arrived 3 hours before.
Why does the first sentence use past simple and the second use past perfect? I thought with "before" it was not obligatory to use past perfect. Is it because, in the first sentence, there is no logical relation between the bad things and the quakes? That is: the bad things did not cause the quakes.
In the second sentence, both events are compared. Is that why past perfect is used?