The wise unsure and the sure unwise
In my experience there are two types of ‘smart’. The first recognise the limits of what they know, and they either find someone who can help them or they plan around the gaps. The second are well-read, articulate, certain but are often undone by the things they never thought to consider or the misplaced confidence in their own knowledge.
Call them the wise unsure and the sure unwise.
The wise unsure keep asking questions long after everyone else assumes the answer has been found. They work with others to test what they know, rather than defending it so they can move on quickly.
The sure unwise confuse sounding or assuming they’re right with being ready, then press on regardless.
Most cultures reward the second group. They promote confidence in subject matter and mistake it for competence (especially in managers). Then they act surprised when the unknown unknowns turn up and derail things, as they always do.
The smart ones aren't the problem. The certain ones often are.