Past Perfect is an action that happened before something else in Simple Past, either implied or stated, to emphasize that the first action had been completed before the second one, or to refer to a time period before the action in Simple Past. In a normal sequence of events, there is no need for Past Perfect. You would normally go to the coffee shop first and then drink a coffee, so : I went to the coffee shop and drank a coffee. It wouldn't make sense to say: I had gone to the coffee shop before I drank a coffee, because that would be the normal order of events. But consider these examples: I had gone to the coffee shop before and drunk a latte, so I was surprised it wasn't on the menu any more. I had locked the door before I left, and was surprised to find it ajar, upon my return. I had researched the company before going to the job interview. (The groundwork had been laid.)