On a related note, another problem I see is the lack of awareness of one's own cognitive limitations, and unfortunately, the more one is limited in that area, the less aware of it one tends to be. 

It's difficult to develop expertise, and it takes an intelligent person to realise this. Most people get satisfied with a shallow understanding and stop questioning, thinking they know it all already, you can't teach them anything anymore! They can be very annoying...

Just writing this makes me cringe, I've been there so many times. 😅