Type one diabetes.

So many people think it's no big deal, or that it's purely medical. You just test your blood and can't eat as much cake as you'd like sometimes, right? Oh, they'd hate to be you because they're so scared of needles (“Wow, 5 times a day?! Does it hurt?”) but figure you must just be used to it by now. At least you were allowed to always be front of the dinner queue They wouldn’t mind that perk.