Why past simple "joined", not past perfect "had joined" in this sentence:
His dad joined the army before he was born.
This sentence is from a course of the A.J. Hoge.
My opinion is:
"...before he was born" here is marking of the times, answer to question when and in that circumstances always go past simple. It is as we say:
His dad joined the army last Wednesday.
last Wednesday = before he was born.
Am I right?