Nassim Nicholas Taleb, the contemporary thinker that influences the way I think the most, wrote in his book Fooled by Randomness (also one of my favorite books!) that "I believe that the principal asset I need to protect and cultivate is my deep-seated intellectual insecurity". His motto is "my principal activity is to tease those who take themselves and the quality of their knowledge too seriously".
Cultivating intellectual insecurity instead of intellectual confidence seems to be a strange aim, but sometimes intellectual confidence leads to being certain about things, which is almost always absurd.
Intellectual insecurity is not easy to implement. Therefore, we need to practice purging our minds of the recent tradition of intellectual certainties.