[stylist] Past Tense Usage Question

[Neil Butters]

Hello All,

I have a question about the past simple and past perfect tenses.

  I know when a story is told in the past simple, the past perfect is used for flashbacks or anything else that happened previously. But I have read many stories told in the past simple that seem to ignore that rule in flashback paragraphs. Here is an example from The Last Great Clown Hunt, which is a short story written in the past simple.

  I had glimpsed the stilt dancers only once. Billy Boy and I were watching them through a gap in the big top when the shaman caught us. He ran me off; he
  allowed Billy Boy to stay. I still had a hard time picturing Billy Boy as one of them. To me he'd always seemed like a clown wannabe.

  So why is the past perfect used in the first sentence, cne