What made you buy what you bought, compared to the alternatives that you could have bought?
What was it about that brand of juice, that style of sneakers, those headphones, that kind of perfume or cologne?
How much of your selection had to do with a formulation or some technical feature or a discount price, and how much had to do with an image or an idea?
Sometimes the rational reason is the intellectual alibi for the emotional satisfaction. Pick one of the products you bought and imagine: If that brand were a world, what would that world be like? Where would it be located? What time of day would it be? Who would inhabit it? Then ask yourself, is that world a place you'd like to live? To visit? If so, maybe there's more to your brand choice than meets the eye.