In The Black Swan, Nassim Nicholas Taleb talks about “what you don’t know you don’t know”. It is a pretty complicated but really interesting book. Dense material which I can't possibly compress into a short post like this, because of its brilliance.

One of the interesting topics in the book is about unknown problems. Unknown problems form a risk of an unknown size. They are rare, but if they happen, they could cause big damage. It is impossible to predict these events, because you don’t know what to look for. However, you can guard against these unknown problems with a couple of simple ideas:

• Don’t waste time to try to predict rare events. We’re notoriously bad at predicting things, especially rare events. Focus on your strengths instead of spending your time coming up with a list of stuff that could happen.
• Avoid overspecialization. I mentioned this before in the t-shaped professional, but by spreading knowledge and skills you have a far better chance of surviving unknown things that will happen.
• Love redundancy. In name of economics and optimization, we’re always looking for ways to remove duplication. While this is helpful, it does not make us more resilient when bad things happen. Our bodies are equipped with a lot of double things we could miss. It is just because of this humans are pretty good at surviving. If you're streamlining, make it a conscious choice between less weight and robustness.