 Let me just put on the table here a really key psychological term called anti-fragility. It's a term, it refers to the property of systems that are not fragile. They actually, you know, something is fragile, you've got to protect it. Like glass is fragile, you don't want it to bang around, it'll break. But there's some things that need to bang around. They need to be stressed and challenged in order to develop properly. So bones and muscle are that way. If you take it easy on your muscles, you get weak. If you push them to the point of pain, you get strong. The immune system is that way.