Hard to pick a favourite, of course, but there's a warning against confirmation bias that cautions us against standing firm, to move with the evidence like grass in the wind, that has stuck with me.

On the general discussions of what sort of book I want, I want one no more than a couple of hundred pages long which I can press into the hands of as many of my friends as possible. One that speaks as straightforwardly as possible, without all the self-aggrandizing eastern-guru type language...