I always figured the alcohol thing was more about the hard stuff. I can see where 190 proof Jack could screw you up a lot of different ways if you were in a survival situation. The weak stuff like beers, wines, grog, etc... doesn't have much alcohol in it. Years ago it was the larger percentage of what people drank. Sailors mostly drank the low alcohol stuff (and some rum....arrr!) on long voyages. It keeps better than water, what's it going to do, ferment and go bad? The alcohol kills all the nasty germs so it was the safest thing to drink. Our ancestors weren't a bunch of drunks, they were survivors. (I'm not much on beer myself, but I like Stella. Let's see, a gallon a day for each person. Ouch! that could get expensive.)

Always thought the caffeine thing was kind of stupid too. I went for a period in my life where the only thing I drank was Dr. Pepper. Maybe I should be dead already.

About wearing a hat. Probably just a smart thing to keep your core areas covered in the cold. And your head IS a core area. A big puffy vest, while looking kind of dorky, works amazingly well at keeping you warm.

Another myth I've always thought was stoopid is the swimming after you eat. Don't even mention the word swim while you're eating around my grandmother. She'll start telling you about disfigurement, maiming, and death while sizing you up for a coffin. And nothing will change her mind. O.K. not really survival related, but I guess if you have to swim across a river after eating your fill of snare caught wood rats and black berries you won't die from cramps.