Some are in a period of decline. Their historic success has stopped them being self-aware.
You have achieved great things! Yes, you are super smart! You are used to flatter and triumph.
Problem is, if you truly are the smartest one around, why look at others for insight? Better to look at yourself!
Now, this is when you are in danger of falling for the myth of your own genius. You stop looking outward.
Debate, so crucial for progress, gets shut down.
There are stronger ones. In fact the strongest are the most open to challenge and dissent.
It takes some effort to question methods that have successfully worked in the past. But without it, one turns inwards.
Change is everywhere, constant and relentless. The moment you think you know it all, you are destined for stagnation.