Paul Graham writes about his heroes: people who have significantly influenced his life. One of those people is Robert Morris:

Robert Morris has a very unusual quality: he’s never wrong. It might seem this would require you to be omniscient, but actually it’s surprisingly easy. Don’t say anything unless you’re fairly sure of it.

Here’s the insightful bit though:

He’s not just generally correct, but also correct about how correct he is.

You’d think it would be such a great thing never to be wrong that everyone would do this. It doesn’t seem like that much extra work to pay as much attention to the error on an idea as to the idea itself. And yet practically no one does.

This is a quality I’ve tried to develop recently: don’t just try to get the right answer, try to estimate how correct that answer is, and act accordingly.

In fact, I usually try to go one step further: improve confidence in the answer by testing, verifying, getting second opinions, etc. It ends up being a lot of work, but in many cases it’s well worth the effort — in fact, it’s the only way to achieve success for many complex problems.