“Lesson overall” can contain idiosyncratic facts that you can learn iff you run into problem and try to solve it, you can’t know them (assuming you are human and not AIXI) in advance. But you can ask yourself “how would someone with better decision-making algorithm solve this problem having the same information as me before I tried to solve this problem” and update your decision-making algorithm accordingly.
“Lesson overall” can contain idiosyncratic facts that you can learn iff you run into problem and try to solve it, you can’t know them (assuming you are human and not AIXI) in advance. But you can ask yourself “how would someone with better decision-making algorithm solve this problem having the same information as me before I tried to solve this problem” and update your decision-making algorithm accordingly.