You probably already know about this, Dennett, but just in case: when my sugars are running low I get very grouchy and contrary (Deb says, “Unusually so”) and argumentative (“Unusually so, Deb? Debster? Luv?”). Several hours without food usually has me on edge… and stupid, and forgetful.
Would not have helped Ben in the scenario you outlined, but for me I always carry Life Savers. Flavor doesn’t matter, because when I start to feel off I just chew them rather than suck them to speed up the glucose absorption. Two candies keep me going for about an hour, but YMMV. I can keep a roll in my pocket for months, they never go bad (“linty” is not “bad,” I just brush them off 😁). And just two keeps me from ramping up my sugars too much.