Actually, introspection is out as well
https://www.businessinsider.com/marc-andreessen-zero-introsp...
https://www.businessinsider.com/marc-andreessen-zero-introsp...
These people are completely detached from reality. How do they think we know the thoughts of these so called great men?
Many have biographies and autobiographies. Is not hard to spot.
"A great king would not self doubt so I will not self doubt".
His blog in 2007, which people loved:
https://pmarchive.com/guide_to_personal_productivity.html
Search for "Anti-Todo" and read that section. Then tell me he doesn't believe in some introspection.