It wasn't the SAS selection process, but a couple of years ago, at an all day event with my Beaver Scouts (5-7 yo), the lunch menu was burgers for the grown-ups. I missed the morning snack but gratefully accepted a burger from someone around noonish.

After spending the day in the hot sun, carrying a day pack that probably held 30 pounds of FAK, meds, water bottles, sunscreen, extra hats, etc., hiking with that pack on my chest and a kid on my back at almost every turn, well hydrated but with no rest breaks or snacks for me since about 6:30am (LOTS for the kiddos), and then making several trips on foot hauling tired kiddos and wagon loads of sun tents, food coolers, water coolers, blankets and lawn chairs back to the cabin, my feet and back were achy, I was headachy and beyond hungry.

I finally ate that burger about 6:45pm. The cheap processed beef patty, cheese, bun and dab of ketchup had congealed into an indescribable warm, blob-like brick that had little resemblance to a hamburger or even food. I'm sure the Food Inspection people would have fainted if they knew I was even considering eating it. I have never eaten anything better in my life.