I agree with the tribal campfire theory. However theres a combined analogy with the concept that if you have to ask the price of a Rolls Royce you can't afford it...and the oft quoted words of Sir Edmind Hilary. Theres nothing complex to it, its a lark.
Funniest sight was when one eventually set fire to the newly laid tarmac at Aldergrove.
A Royal Marine passing through a RAF base once told the Groupie/PMC the morning after he would like his residual Viking genes to be taken into consideration before the punishment was decided !