Keen draws extensively on the economist Hyman Minsky, who argued that financial instability is not an external shock to otherwise stable economies — it is endogenously generated by the system itself during periods of stability. The mechanism works like this: during long periods of economic stability and growth, risk perceptions fall. Lenders become more willing to extend credit on weaker terms. Borrowers take on more debt relative to their income. Asset prices rise, which validates the lending and encourages more borrowing. Eventually, debt servicing costs rise to the point where they are unsustainable. When the first borrowers default, lenders tighten. The credit contraction spreads. The crisis is the result of the boom, not of an external event. For anyone managing money or building a business: the practical lesson is that the safest financial environments are precisely the ones that create the most dangerous conditions for the future. Long, stable periods should increase your caution, not reduce it.