When we were back in the good old US of A, I didn't really enjoy grocery shopping, but had it down to a science. I printed my own shopping list with items arranged to fit the way my store was laid out. We mainly bought the same things every week, so I would just get one of my lists and circle what we needed. If anything special was needed there was room to write it in in the appropriate area. Then I would just go down the aisles tossing in what was on the list. Easy Peasy!
But down here in Central America things are WAY different. I rarely go to the same store more than twice, things are arranged differently, most of the labels are in Spanish, the packaging is different, and the selection is limited. Added to all that, we usually have to take a bus or taxi to and from the store and then schlep all our groceries down the docks to our boat. Consequently, a trip to the store is an adventure that often takes hours.
Above you see how lots of the products are packaged here. For people without refrigeration, these small squeeze packets with a re-sealable caps are a great idea. And they come in small quantities, so are probably used up immediately anyway.
Because it's so humid here, many things are packaged in plastic so they can't absorb moisture. Sugar, flour, salt, beans, pasta, cereals, and crackers all come that way. By the way, that pure cane sugar up there could have been grown within a mile of our boat. This area is full of sugar cane fields and frequently, when they are burning them off in preparation for harvest, it rains black ash on our boat.
Other products come in these foil-lined boxes similar to the juice boxes you put in a child's lunch, but with a re-sealable cap. I really like these because they stack so neatly in the pantry locker, and can be folded flat when empty to take up less space in the garbage bin. (If I was Salvadoran, I'd just throw it out on the street, but that's a whole 'nother subject!) The milk is particularly brilliant because it requires no refrigeration before opening. WHY don't they sell this in America?
So, combined with the strange packaging, foreign labels, limited selection, difficulty of getting things back to the boat, and the cheap restaurant prices, it's no wonder cruisers eat out so often.