Have done some homework.
Generally, hanging means that the naturally occurring enzymes start beaking down the muscle protein into amino acids, glycogen and glucose and the fats into aromatic fatty acids. All of which, apparently, are responsible for the meatier taste one gets from aged (hung) meat and extra tenderness.
Processing meat too soon after slaughter means that one is left with meat which is still in a state of rigor mortis - so the final product is tough and tasteless. Poultry need a day or two and pigs need 'several' days, but I'm not sure if this actually includes the time spent in a fridge prior to cooking.
I reckon you can mitigate the problem of 'young' meat by ensuring it is at room temperature, for a bit, before cooking and that you leave it aside after cooking for 10-15 minutes before carving , or whatever.