So true! Especially if they’re men. Masculine training encourages that kind of unwarranted confidence.
Women, OTOH, tend to be more certain they know their shit before they venture forth. One reason for that is that women are so often doubted when they do so (both their intelligence and their abilities), largely by men but sometimes also by other women.
Knowing that there’s a great chance you’ll be doubted and asked to prove what you’re saying or justify what you’re doing often encourages women to be more certain that they can back up what they’re saying or doing. Pretty ironic, then, that in so many situations, men still doubt what women say and do so much more than they doubt what other men say and do.