I absolutely do this, and was just talking about this to another American expat friend today!
I'm down in London at the moment visiting and she and another expat friend took me to the food hall at Selfridges, where I spent too much money on Jelly Bellies and chocolate and Crisco - though I managed to pass up buying things just for the sake of having American food in the house! This time, anyway. Back in Middlesbrough, over the past two months I've bought Oreos, Ritz crackers, and several other American things that I subsequently haven't touched, just because they were familiar brands and having them in my cabinets to look at makes me feel less homesick.
And don't even get me started on Pizza Hut. I'm a Papa John's girl, and yet I think I've eaten there four times in eight weeks, when I'm pretty sure I haven't eaten Pizza Hut in the States more than four times in two years.
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