This document discusses how product teams can navigate crises by accepting unknowns, sticking to principles, and owning basics. It describes BlaBlaCar's experience during the COVID-19 pandemic from February 2020 to Summer 2022. During this period, BlaBlaCar tried different approaches like allowing more seats or removing fees but saw low usage. They emphasized not trying to predict the future, sticking to principles like maximizing revenue while preserving dynamics, and regularly examining principles to keep improving. The document encourages always looking at principles to fully realize their potential even during crises.