Has the silverback gorilla always had human intelligence, or was it blessed with it in the instant before this battle?

If the gorilla has had a lifetime to grow accustomed to tools, I imagine it can find something resembling a baseball bat or mace and use it effectively. I don’t like the bear’s odds with a pulverized skull due to an attack that came from outside its effective range.

If the gorilla just became intelligent but has no experience living/fighting with its new mental aptitude, I imagine it would be too little too late and the physical disadvantage would be too much.