contrary
Actually, I had to get some sleep, but finally I stayed up all night long. But I noticed that I don't have to sleep contrary to my condition. I'll stay up all day long today. I become sleepy right now. I may possibly take a nap for some while. I know it is difficult to stay up all day contrary to my condition. No matter how much difficult it is, I have to get up at least in the evening, namely before noon.