This will surely seem like a total newbie question. (Is there a rbpt
FAQ?)

After purchasing a kayak, I found that part of the culture appears to
be a ritual pilgrimage to buy a membership in the Mountain Equipment
Coop (in Canada). This I dutifully attended to yesterday afternoon.
After completing the form, I strolled around my local outlet.

I marvelled at all the cool toys and was impressed by the quality and
price of the Farmer Johns. It then struck me: I hadn't a clue, should I
ever buy one, what one wears under them. Are they like the Scotsman's
kilt?

Any help in this regard or anything else I ought to know about these
things would be welcome.

Cheers,
Wilf