(as) wise as an owl

Exceptionally wise, discerning, or sound in judgment. The owl was once a symbol of Athena, the Greek goddess of wisdom, and has endured as a symbol of wisdom throughout the ages. She is considered as wise as an owl and has become something of a matriarch within the community. You'd think he'd be wise as an owl after so many years in this industry, but he's still a careless old fool.