1.
Hubris kills. When you're winning, the temptation to chase shiny objects (tech! politics!) pulls focus from the core business that made you successful.
2.
Distribution is destiny. Under Armour bet on malls and Sports Authority while Nike built owned stores and went direct — that channel blindness cost them $120M overnight and long-term relevance.
3.
Premium brands can't discount their way out. Once your gear floods TJ Maxx, the cool kids move on — and cool was Under Armour's entire moat.