People need to stop mixing "knowledge" and "intelligence". It's true that a magician can, will and have read and learned more books than the average person, and a barbarian might not know all the rule to live with more civilised person, but it's only knowledge.
Intelligence is knowing that even with all your knowledge, you might not be the more suited person for the task at hand. For example, dealing with a tribal spirit without getting the party slaughtered. Here, the barbarian who knows this spirit have more chance to success than the magician who only saw it in books. -- Anon Guest
Knowledge is remembering that tomatoes are a fruit. Intelligence is not making a conserve out of them. -- the wisdom of Tumblr.
"They're just big cats," said the Wizard. "Just remember cat manners and we should be fine." With that in mind, he made a trilling purr noise and offered knuckles for the gigantic feline to sniff.
Unfortunately for the Wizard, they were also Tabaxi Barbarians who understood the Common Tongue. "Puny man try again, puny man get claw in jollies."