You'll be standing in the bakery section at the grocery store trying to convince yourself that these 100% whole wheat bagel thins probably taste just as good as the sweet, dense potato bread you love so much (keep telling yourself that, you poor, sweet, naive baby fawn) and without warning, you're suddenly made stomach-growlingly aware that you'd like nothing more than to tear into and devour that entire package of jelly rolls on the bottom shelf. And they're not even the good ones!* They're some Mexican brand name you can't pronounce, and there's really no telling how long they've been on the shelf (Do I detect a thick layer of dust on the box? Eh, that'll come off. You're in this for the carbs, not the cardboard) but the cartoon bear on the front is winking so convincingly that you're sure you'd be willing to trade your firstborn just to lick the finger of someone who'd recently taken a bite of one.
If you've never dieted then
*And by good ones I of course mean Little Debbie®, manufacturer of all things that are good and holy.