A black swan is an unpredictable event that is beyond what is normally expected of a situation and has potentially severe consequences. Black swan events are characterized by their extreme rarity, their severe impact, and the widespread insistence they were obvious in hindsight. - Jim Chappelow - Investopedia
https://www.investopedia.com/terms/b/blackswan.asp
Black Swan and Anti-Fragile were two of my favourite books consumed last year. These are 2 of 5 books in Nassim Nicholas Taleb's Incerto series. I enjoyed Skin in the Game as well, but these two drove the message home for me. Now is a good a time as any to read them. You won't be going out much.