Before low carb I could eat the same thing every day and never get bored, if it was a bag of Doritos. Modern products are deliberately engineered to stimulate our endocrine system to an extent that our natural diet doesn't. All that salt, sugar and less straightforward texture manipulations and "flavorings" like MSG. That's how you can be walking through a store, not especially hungry, and something that isn't even food (though it's sold as such) can practically leap off the shelf and grab you by the hypothalamus. It's exciting all right, like jumping off a cliff.