In page xxxi of PROLOGUE, a sentence like below rises up:
As I explained in the chapter called "The Uncertainty of the Phony", for all of their intellectual appeal, these niceties have no serious implications Monday to Friday as opposed to more substantial (but neglected) matters.
I don't really know the sentence from "no serious implications Monday to Friday as opposed".
Why here suddenly comes up a "Monday to Friday", I can't get through to it.
"Monday to Friday" is used here to mean "usually" or "on an everyday basis". He is saying that "these niceties" are theoretically interesting but not of any practical significance or importance.
What he is emphasising here is that in your leisure time (i.e. at the weekend) these ideas might be fun to debate or investigate. In a more business-like context (i.e. during the week) the profit to be made from these is insignificant compared to other factors.
It is a common theme from Taleb to use financial decisions as a way of exposing the impact of probabilistic interpretations. If you ask someone in business to give you some of their time during the week, you take them away from their income stream - so they expect the question to have a substantial reward (or at least the chance of such). At the weekend, they could instead expect you to entertain them with clever tricks or puzzles.
