So, basically, they were making stuff up as they go along while at the same time showing off that they could do things just because they could? I actually find that somewhat comical for some reason. In all seriousness though, I hope we've learned some kind of lesson out of all of this. It'd be pretty hard not to.
The problem is that economics is a social science so lesson learned is subject to fashion. They will teach you in History about how the New Deal saved America; they will teach you in economics that it prolonged the depression, but only if you get a teacher who believes Friedman. This is why Piketty went back to France.
All good points I agree with. Additional to learn lessons one needs to admit failure, the the moment japan is touting their economic policy as a success. The fashionable lesson right now is that bailouts and helicopter money drops work to boost the economy.