I know, but the question was where this occured. Nearly no point originates with the person you hear it from or the school of thought. David Allen's insights in productivity derive from other people and Jaynes' views on probability theory in turn derive from thinkers before him.
Sometimes our minds suddenly "click" and we see a topic in a new light. Or sometimes we think we understand an idea, think it's stupid and ignore attempts to explain it ("yeah, I already know that"), until we suddenly realize that our understanding was wrong.
This kind of insight is supposedly hard to transmit, but it might be worth a try!
So, what kind of important and valuable insights do you wish you had earlier? Could you try to explain briefly what led to the insight, in a way that might help others get it?