An 'impulse buy' is when you buy something without planning to do and usually without thinking about it carefully. bean = been

An impulse purchase, that’s what it was.

An 'impulse buy' is when you buy something you don't really need and didn't plan to buy. You go into town to buy some shoes see a shirt you love so you buy it even though you don't really need it. It had been. You are talking about a time in the past but before another time in the past. When I arrived (in the past) he had left (he left before I arrived). Does that help? Please ask if you need something else?