I will agree based on anecdata alone. I have a high IQ, but have achieved much less than you might predict based on that IQ alone--primarily out of lack of desire.

Even though on paper I may be high-potential, in real life I'd prefer to be normal, and for every one of me that exists, there's a 100 IQ person who has the drive and willpower to achieve things that would be considered atypical. Both of us are exceptions, but we both still exist.