Followup to: The Most Important Thing You Learned
What's the most frequently useful thing you've learned on OB - not the most memorable or most valuable, but the thing you use most often? What influences your behavior, factors in more than one decision? Please give a concrete example if you can. This isn't limited to archetypally "mundane" activities: if your daily life involves difficult research or arguing with philosophers, go ahead and describe that too.
'yep. I'll second this.
Really, if you understand "the bottom line", you could reliably reinvent the whole of rationality for yourself. And once you have read and internalized it, you walk around the world noticing people justifying things to themselves all the time.