I'm wording this terribly but I'll give an example or two to show what I mean.
I was on holiday in the Dominican Republic and I was very ill from the malaria pills we'd been advised to take and could barely eat the whole time there. We went to a local store after 5 or so days of this and bought Milky Way bars(U.S Mars bars), cans of Cola and little tubs of plain Pringles. The food stayed down and somehow tasted incredible. I still dream of that meal.
Also the packs of little biscuits you get in hotels. I buy biscuits at home but somehow I get excited by seeing what mini packs of biscuits they have. Also the tea selection.
And when I was a kid, those little multipack boxes of cereal somehow always tasted much better than cereal from the big packs.
Does anyone else have any other examples? It doesn't have to be food related.