When action is needed, optimism, even of the mildly delusional variety, may be a good thing.

Courage is willingness to take the risk once you know the odds. Optimistic overconfidence means you are taking the risk because you don't know the odds. It's a big difference.

In a rising market, enough of your bad ideas will pay off so that you'll never learn that you should have fewer ideas.

It is the consistency of the information that matters for a good story, not its completeness. Indeed, you will often find that knowing little makes it easier to fit everything you know into a coherent pattern.

If individuals are rational, there is no need to protect them against their own choices.

We can be blind to the obvious, and we are also blind to our blindness.

Banks are run by executives, and executives protect themselves, and that does not always mean that banks are going to behave rationally.