In the military we preach resiliency. But resiliency only means the individual or system can withstand the shock. What we really want is the individual or system to get stronger because of the shock.
Anti-fragile: Anything that has more upside than downside from random events (or certain shocks). The reverse is fragile. Things that remain steady in adversity are resilient.
Homo-sapiens are anti-fragile. Humans are fragile. Hence the 100 year life span. It allows genetic code to adapt to shocks to the system and improve the overall fitness of homo sapiens. It can't happen too fast or it might over correct.
The Marine Corps is anti-fragile. Marines are fragile. Hence the 20 to 40 year career limit. It allows new leadership to enter and adapt to shocks to the system and improve the overall fitness of the Service. It can't happen too fast or it might over correct.