No two people see the world exactly alike, and different temperaments will often apply the same principle, recognized by both, differently. Even one and the same person won't always maintain the same views and judgments: earlier convictions must give way to later ones.
Some things don't last forever, but some things do. Like a good song, or a good book, or a good memory you can take out and unfold in your darkest times, pressing down on the corners and peering in close, hoping you still recognize the person you see there.