I've also found I'm much happier with my choices when I don't compare them to might-have-beens. This is much easier to do if I don't even bother to become aware of the alternatives (for instance, ordering the first menu item that seems likely to be satisfying). It reduces my wistfulness for what might have been :)
This writeup at Ars Technica about a recently published paper in the Journal of Consumer Research may be of interest. Super-brief summary:
If this is right (which seems plausible enough) then it presumably applies more broadly: e.g., to what tactics are most effective in political debate. Though it's hardly news in that area that making people feel stupid isn't the best way to persuade them of things.
Abstract of the paper: