They say had is only when an action was completed (finished or "perfected") at some point in the past before something else happened.
But i recently heard a sentence from Fault in Our Stars:
Hazel says I didn't believe a word. But that's okay.
I knew this was the right thing to do. Funerals, I had decided, are not for the dead. They're for the living.
Shouldn't it be decided, not had decided as no other event is mentioned there after or before that?