Campo,
Maybe its that you get so cold.
Much of my preparation for the coming day is about comfort. Even though it was 9 degrees when I went out at 5 AM friday morning and never got above freezing I was prepared and kept warm all day.

Now I will tell you that I hunt out of a pop up ground blind when it's very cold. That seems to help. Plus it's very comfortable.

I can barely sleep when I know I'm hunting the next day. True, it's only my second year hunting but so far there have been many nights I just never made it to sleep. If I knew that what I had to look forward to was to "freeze my a** off" the next day, I might want to stay in bed too. Ok probably not but it would make it harder to get out