Don't you dare call me optimistic. (It's a) grave insult.

The fundamental guideline for not deploying optimism is to ask what the cost of failure is in the particular situation. If the cost of failure is high, optimism is the wrong strategy.

I don’t believe in optimism. I believe in optimal behavior. That’s a different thing.

False optimism sooner or later means disillusionment, anger and hopelessness.

He’s too superstitious not to see this as a bad omen, but when you're a pessimist, all omens are bad.

[W]e're entering the most dangerous phase in the region in decades. I'm really not all that hopeful.

Don't be too assuming, it doesn't get you anywhere.

Market optimism that this time is different is misguided and dangerous.

La esperanza no es un buen plan.

For a certain period of time, things won't be easy for us. We shouldn't be expecting good news.

Don’t partner with pessimists

The sad thing about the optimist is his state of mind concerning himself.

Being an optimist after you've got everything you want doesn't count.

["DONALDSON: But on Friday, you were very pessimistic. You said, "No good," when someone asked you how things were going."] No, I'm saying even now, if I have to summarize the situation - in one word it's good, in two words, not good.