I’ve got a fair amount of fat and muscle on me. That could be a factor though. Maybe one of the reasons I don’t bruise easily is because I absorb the blows better than I used to. Back when I was bruising constantly I had alarmingly little body fat.

Combined with some of the stuff other people have mentioned, I can see there being enough factors piled on that the injury would have to be really severe before I start having noticeable bruising.