So once you've decided on a particular brand and variety of chips you only ever buy that single brand and variety of chips, never branching out to try different things? Never get an urge for wavy chips instead of traditional, or maybe tortilla chips the next time, maybe even every now and then cheese curls?
I don't even like Sardines but I definitely understand there's a ton of variety in flavors and packing styles and even the species of fish can be a little different.
Some people would happily eat the same thing for breakfast, dinner, and supper every single day for the rest of their lives. I don't necessarily understand it, but I've met plenty of people like that.