I used to say simply having common sense, but wisdom is fine too: plenty of smart, intelligent people lack the most common of common sense (I have no idea why it's called "common" when it's anything but — in Serbian, we say "zdrav razum" or "healthy sense/reason" which is slightly better).
I found it particularly funny when my University math professors displayed a complete inability to reason about the simplest of things.
"Common sense is the best distributed thing in the world, for we all think we possess a good share of it." — René Descartes, Discours de la Méthode (1637) (Or in French: "Le bon sens est la chose du monde la mieux partagée, car chacun pense en être bien pourvu.") In some philosophies, what stands opposite of wisdom is not folly, but common sense. However, it might be possible that neither common sense, nor wisdom will bring you happiness: the former is unable to provide it, the latter is unable to be attained (philo-sophia, an asymptotical wanting of wisdom).
I found it particularly funny when my University math professors displayed a complete inability to reason about the simplest of things.