i think it also depends on what style of cuisine you like to eat/cook.

e.g for me, asian fish sauce, sesame oil, coconut cream in tins, kaffir lime leaves ARE staples. but if you weren't into asian food, they wouldn't be.

i think of staples more as

flour
sugar
salt
milk
baked beans

as in, the minimum you HAVE to have when you go camping, so that in the barest situation, you can make SOMETHING edible.

i would first make a list of what you like to cook, and then think about what you need to make those dishes, i think that will give you a good list of what to go and stock up on for next supermarket trip.

and some staples are perishable e.g fruit and vegies, meat.