Black swan
The thing that none of your doctrines of precedent, policies, procedures, or other organisational scar tissue can possibly equip you to deal with. Validation of the truth, universally acknowledged but in risk management, that past performance is no guarantee of future performance. Also the title of a bombastic but basically entertaining book by [[]]
And a small cafe on the crest of a hill on the road from Christchurch to Akaroa, but I might be imagining that.