"I'm encountering, anew, the "your warmer in your bag without layers. even naked". I really am having a difficult time posing a clear, concise, CONVINCING argument for this theory that, even I, naively espoused many, many years ago."
This is a clearly proven theory that really should not be debated. It has stood many of us in very good stead for many many years, and personally I think it's mean spirited and unfair for a bunch of old guys (including me) to disprove it just because it may not be true.
Essentially my experience as a young(er) man went along the lines of
..Go camping a few times
..Go to Uni
..Meet an attractive young lady
..Convince her to come camping with me (possibly on University O week)
..Lend her my spare (spare) sleeping bag
..Explain to her as she's shivering at night, how much warmer it is sleeping naked, as I now am
..Once I have convinced her of this, and she still fails to stop shivering, gallantly offer to swap sleeping bags
..(Cross my fingers when I promise not to look)
..Finally allow her to persuade me to zip the two bags together when my chattering teeth are still keeping her awake a couple of hours later.
For the benefit of geeky 18-21 year old guys across Western Civilisation who own a tent and a sleeping bag, I think we should cease and desist this thread from here on. (And for the benefit of tour group leaders of multi-national campers who clearly have experience which we do not)