It leaves me feeling like the unarmed opponent in the game of wits!
Me too.
For instance, I can only fuzzilly deduce that the term you used - yaknow - is a corruption of Yak now. This, presumably (and I'm awful at looking things up) comes from Tibet, and refers either to a) the desire to eat yak stew, now, or b) using Yak as the word to refer to part of a yak (isn't this the opposite of synecdoche?), a desire for a steaming bowl of yak milk.
Given that Tibetans are not famous for wordplay, I would have to further conclude that it is not an aspect of working class Tibetan culture being spread here, but perhaps one from the intelligentsia - viz the lamas. Now they are more than likely to have been vegetarian, in which case one must conclude that this is perhaps the final sentence in a zen koan that makes sense to initiates, but sounds like one hand clapping to us.
Allowing my imagination to run free, I presume the story would go something like this:
A student approached the Master one day and said, "Master, I meditate. I understand the fourfold path. I follow the eight rules. Yet my belly feels empty."
And the Master, raising a finger at a passing working class devotee, said: "Yak now". And the student understand all.
I obviously need more drugs...
