Well see that's the thing Asura. Everyone has some form of self regeneration, but it's not like Jaune who can put it onto overdrive, or like Lyndsey's who can accelerate others. It's more akin to "You won't die immediately from a mortal wound" like getting stabbed or thrown into a mountain. You know, like being able to go all the way down to negative 10 health in the more recent DnD books; you're out of commission after zero, but you can still be saved. For most people that's all they can do. For Jaune, maybe that means he can still act even after negative ten. Or whatever.