Also, note:

One way to interpret Kay saying "I invented objects" is that he is claiming to have invented the first conception of objects that anybody gave a damn about (which is absolutely true).

Even though C++ doesn't have anything Kay would call an object, the reason C++ exists is that C programmers were jealous of Smalltalk. (Again, while C++ is more popular, objective C actually looks & acts sort of like Smalltalk & provides some of the benefits -- C++ is something basically unrelated that appropriated the ad copy in order to cash in on the hype, though only actual Smalltalk users would have been able to call Stroustrop's bluff in the 80s.)