What did we learn from it and why the next crisis will come
The reason why the world has fallen to persisting financial crisis is systemic. It is based on wrong incentive structures and response/control that do not match with the complexity of the system. As long as we do look deep enough to the fundamental flaws of the system and act upon it, we shall fall into this trap time and again. We are already building the next crisis. However, we are not necessarily doomed to repeat it forever, but this requires a new system where human greed is harnessed for a good purpose.