I think the lesson learned is that the system is setup to encourage this kind of bandwagon investment. For example, all the people who are buying houses as a vehicle towards financial security: completely rational within the confines of the system we have. But causing huge problems, and therefore something that shouldn't be incentivised.
I'm seeing it in the sense of gambling: I buy when I think it's going to go up, you sell because you think it's going to go down (stocks), but people don't think, they just get excited, bubble happens, then we get a small minority winning big and the majority losing.