Over the course of a day, you just lie. You try to lie still in your bunk and just, like, read a book or something, but you feel, like, this tingling. And then after about a day of that, they get you all the way back to sea level slowly. So that the nitrogen, what? You know what it is? It's like if you take a can of soda and you shake it up. If you open it, open the top quickly. But if you open the top really slowly and you let it slowly come out, you don't get all the bubbles right. It's that same effect.